Commit graph

49 commits

Author SHA1 Message Date
Mechiel Lukkien
ebb8ad06b5
use shorter smtp.NewAddress() instead of smtp.Address{...} 2024-05-09 21:26:22 +02:00
Mechiel Lukkien
83004bb18e
give more helpful pointers for dns-related settings
in quickstart, add troubleshooting hints.
in suggested dns records, explain the multiline long dkim record should
probably be converted into a single string.

the quickstart output is quite long already. i'm hoping for a "mox setup" in
the future where we help a user step-by-step to a fully working system. we'll
have more space to prevent hints and check the settings after a user made
changes. it's on the roadmap.

based on issues #158 and #164, thanks vipas84 and RobSlgm for reporting and
discussion.
2024-05-09 17:28:29 +02:00
Mechiel Lukkien
30ac690c8f
when removing account, remove its data directory instead of leaving it around
recreating the account would resurface the old messages, certainly not what you'ld expect.
it's about time to just remove the files. we do ask admins to confirm that when
removing through admin interface. it's also in the "mox config account rm" help
output now.

for issue #162 by RobSlgm with feedback from x8x, thanks!
2024-05-09 16:30:11 +02:00
Mechiel Lukkien
32cf6500bd
when removing an address, remove it as member from aliases
unless the address is the last member, then the admin must either remove the
alias first, or add new members. we don't want to accidentally remove an alias
address.

in the admin page for removing addresses, we warn the admin that the address
will be removed from any aliases.
2024-04-28 11:44:51 +02:00
Mechiel Lukkien
960a51242d
add aliases/lists: when sending to an alias, the message gets delivered to all members
the members must currently all be addresses of local accounts.

a message sent to an alias is accepted if at least one of the members accepts
it. if no members accepts it (e.g. due to bad reputation of sender), the
message is rejected.

if a message is submitted to both an alias addresses and to recipients that are
members of the alias in an smtp transaction, the message will be delivered to
such members only once.  the same applies if the address in the message
from-header is the address of a member: that member won't receive the message
(they sent it). this prevents duplicate messages.

aliases have three configuration options:
- PostPublic: whether anyone can send through the alias, or only members.
  members-only lists can be useful inside organizations for internal
  communication. public lists can be useful for support addresses.
- ListMembers: whether members can see the addresses of other members. this can
  be seen in the account web interface. in the future, we could export this in
  other ways, so clients can expand the list.
- AllowMsgFrom: whether messages can be sent through the alias with the alias
  address used in the message from-header. the webmail knows it can use that
  address, and will use it as from-address when replying to a message sent to
  that address.

ideas for the future:
- allow external addresses as members. still with some restrictions, such as
  requiring a valid dkim-signature so delivery has a chance to succeed. will
  also need configuration of an admin that can receive any bounces.
- allow specifying specific members who can sent through the list (instead of
  all members).

for github issue #57 by hmfaysal.
also relevant for #99 by naturalethic.
thanks to damir & marin from sartura for discussing requirements/features.
2024-04-24 19:15:30 +02:00
Mechiel Lukkien
1cf7477642
localserve: change queue to deliver to localserve smtp server
instead of skipping on any smtp and delivering messages to accounts.
we dial the ip of the smtp listener, which is localhost:1025 by default.

the smtp server now uses a mock dns resolver during spf & dkim verification for
hosted domains (localhost by default), so they should pass.

the advantage is that we get regular full smtp server behaviour for delivering
in localserve, including webhooks, and potential first-time sender delays
(though this is disabled by default now).

incoming deliveries now go through normal address resolution, where before we
would always deliver to mox@localhost. we still accept email for unknown
recipients to mox@localhost.

this will be useful upcoming alias/list functionality.

localserve will now generate a dkim key when creating a new config. existing
users may wish to reset (remove) their localserve directory, or add a dkim key.
2024-04-24 11:40:22 +02:00
Mechiel Lukkien
e702f45d32
webadmin: make remaining domain settings configurable via admin web interface
for dmarc reporting address, tls reporting address, mtasts policy, dkim keys/selectors.

should make it easier for webadmin-using admins to discover these settings.

the webadmin interface is now on par with functionality you would set through
the configuration file, let's keep it that way.
2024-04-19 10:23:53 +02:00
Mechiel Lukkien
a69887bfab
webadmin: make routes configurable: globally, per domain, per account
this simplifies some of the code that makes modifications to the config file. a
few protected functions can make changes to the dynamic config, which webadmin
can use. instead of having separate functions in mox-/admin.go for each type of
change.

this also exports the parsed full dynamic config to webadmin, so we need fewer
functions for specific config fields too.
2024-04-18 11:14:24 +02:00
Mechiel Lukkien
09fcc49223
add a webapi and webhooks for a simple http/json-based api
for applications to compose/send messages, receive delivery feedback, and
maintain suppression lists.

this is an alternative to applications using a library to compose messages,
submitting those messages using smtp, and monitoring a mailbox with imap for
DSNs, which can be processed into the equivalent of suppression lists. but you
need to know about all these standards/protocols and find libraries. by using
the webapi & webhooks, you just need a http & json library.

unfortunately, there is no standard for these kinds of api, so mox has made up
yet another one...

matching incoming DSNs about deliveries to original outgoing messages requires
keeping history of "retired" messages (delivered from the queue, either
successfully or failed). this can be enabled per account. history is also
useful for debugging deliveries. we now also keep history of each delivery
attempt, accessible while still in the queue, and kept when a message is
retired. the queue webadmin pages now also have pagination, to show potentially
large history.

a queue of webhook calls is now managed too. failures are retried similar to
message deliveries. webhooks can also be saved to the retired list after
completing. also configurable per account.

messages can be sent with a "unique smtp mail from" address. this can only be
used if the domain is configured with a localpart catchall separator such as
"+". when enabled, a queued message gets assigned a random "fromid", which is
added after the separator when sending. when DSNs are returned, they can be
related to previously sent messages based on this fromid. in the future, we can
implement matching on the "envid" used in the smtp dsn extension, or on the
"message-id" of the message. using a fromid can be triggered by authenticating
with a login email address that is configured as enabling fromid.

suppression lists are automatically managed per account. if a delivery attempt
results in certain smtp errors, the destination address is added to the
suppression list. future messages queued for that recipient will immediately
fail without a delivery attempt. suppression lists protect your mail server
reputation.

submitted messages can carry "extra" data through the queue and webhooks for
outgoing deliveries. through webapi as a json object, through smtp submission
as message headers of the form "x-mox-extra-<key>: value".

to make it easy to test webapi/webhooks locally, the "localserve" mode actually
puts messages in the queue. when it's time to deliver, it still won't do a full
delivery attempt, but just delivers to the sender account. unless the recipient
address has a special form, simulating a failure to deliver.

admins now have more control over the queue. "hold rules" can be added to mark
newly queued messages as "on hold", pausing delivery. rules can be about
certain sender or recipient domains/addresses, or apply to all messages pausing
the entire queue. also useful for (local) testing.

new config options have been introduced. they are editable through the admin
and/or account web interfaces.

the webapi http endpoints are enabled for newly generated configs with the
quickstart, and in localserve. existing configurations must explicitly enable
the webapi in mox.conf.

gopherwatch.org was created to dogfood this code. it initially used just the
compose/smtpclient/imapclient mox packages to send messages and process
delivery feedback. it will get a config option to use the mox webapi/webhooks
instead. the gopherwatch code to use webapi/webhook is smaller and simpler, and
developing that shaped development of the mox webapi/webhooks.

for issue #31 by cuu508
2024-04-15 21:49:02 +02:00
Mechiel Lukkien
8b2c97808d
add account option to skip the first-time sender delay
useful for accounts that automatically process messages and want to process quickly
2024-03-16 20:24:07 +01:00
Mechiel Lukkien
15e450df61
implement only monitoring dns blocklists, without using them for incoming deliveries
so you can still know when someone has put you on their blocklist (which may
affect delivery), without using them.

also query dnsbls for our ips more often when we do more outgoing connections
for delivery: once every 100 messages, but at least 5 mins and at most 3 hours
since the previous check.
2024-03-05 19:37:48 +01:00
Mechiel Lukkien
d1b87cdb0d
replace packages slog and slices from golang.org/x/exp with stdlib
since we are now at go1.21 as minimum.
2024-02-08 14:49:01 +01:00
Mechiel Lukkien
da3ed38a5c
assume a dns cname record mail.<domain>, pointing to the hostname of the mail server, for clients to connect to
the autoconfig/autodiscover endpoints, and the printed client settings (in
quickstart, in the admin interface) now all point to the cname record (called
"client settings domain"). it is configurable per domain, and set to
"mail.<domain>" by default. for existing mox installs, the domain can be added
by editing the config file.

this makes it easier for a domain to migrate to another server in the future.
client settings don't have to be updated, the cname can just be changed.
before, the hostname of the mail server was configured in email clients.
migrating away would require changing settings in all clients.

if a client settings domain is configured, a TLS certificate for the name will
be requested through ACME, or must be configured manually.
2023-12-24 11:06:08 +01:00
Mechiel Lukkien
db3fef4981
when suggesting CAA records for a domain, suggest variants that bind to the account id and with validation methods used by mox
should prevent potential mitm attacks. especially when done close to the
machine itself (where a http/tls challenge is intercepted to get a valid
certificate), as seen on the internet last month.
2023-12-21 15:53:32 +01:00
Mechiel Lukkien
d73bda7511
add per-account quota for total message size disk usage
so a single user cannot fill up the disk.
by default, there is (still) no limit. a default can be set in the config file
for all accounts, and a per-account max size can be set that would override any
global setting.

this does not take into account disk usage of the index database. and also not
of any file system overhead.
2023-12-20 20:54:12 +01:00
Mechiel Lukkien
fcaa504878
wrap long lines with many logging parameters to multiple lines
for improved readability
2023-12-14 13:45:52 +01:00
Mechiel Lukkien
5b20cba50a
switch to slog.Logger for logging, for easier reuse of packages by external software
we don't want external software to include internal details like mlog.
slog.Logger is/will be the standard.

we still have mlog for its helper functions, and its handler that logs in
concise logfmt used by mox.

packages that are not meant for reuse still pass around mlog.Log for
convenience.

we use golang.org/x/exp/slog because we also support the previous Go toolchain
version. with the next Go release, we'll switch to the builtin slog.
2023-12-14 13:45:52 +01:00
Mechiel Lukkien
c66fa64b8b
wrap long dkim dns records at 100 characters instead of 255 for better display (no line-wrap) 2023-11-22 14:02:24 +01:00
Mechiel Lukkien
2073db194b
when checking domain settings, check that dmarc & tls reporting addresses are present if there is a record 2023-11-10 20:25:06 +01:00
Mechiel Lukkien
893a6f8911
implement outgoing tls reports
we were already accepting, processing and displaying incoming tls reports. now
we start tracking TLS connection and security-policy-related errors for
outgoing message deliveries as well. we send reports once a day, to the
reporting addresses specified in TLSRPT records (rua) of a policy domain. these
reports are about MTA-STS policies and/or DANE policies, and about
STARTTLS-related failures.

sending reports is enabled by default, but can be disabled through setting
NoOutgoingTLSReports in mox.conf.

only at the end of the implementation process came the realization that the
TLSRPT policy domain for DANE (MX) hosts are separate from the TLSRPT policy
for the recipient domain, and that MTA-STS and DANE TLS/policy results are
typically delivered in separate reports. so MX hosts need their own TLSRPT
policies.

config for the per-host TLSRPT policy should be added to mox.conf for existing
installs, in field HostTLSRPT. it is automatically configured by quickstart for
new installs. with a HostTLSRPT config, the "dns records" and "dns check" admin
pages now suggest the per-host TLSRPT record. by creating that record, you're
requesting TLS reports about your MX host.

gathering all the TLS/policy results is somewhat tricky. the tentacles go
throughout the code. the positive result is that the TLS/policy-related code
had to be cleaned up a bit. for example, the smtpclient TLS modes now reflect
reality better, with independent settings about whether PKIX and/or DANE
verification has to be done, and/or whether verification errors have to be
ignored (e.g. for tls-required: no header). also, cached mtasts policies of
mode "none" are now cleaned up once the MTA-STS DNS record goes away.
2023-11-09 19:47:26 +01:00
Mechiel Lukkien
28fae96a9b
make mox compile on windows, without "mox serve" but with working "mox localserve"
getting mox to compile required changing code in only a few places where
package "syscall" was used: for accessing file access times and for umask
handling. an open problem is how to start a process as an unprivileged user on
windows.  that's why "mox serve" isn't implemented yet. and just finding a way
to implement it now may not be good enough in the near future: we may want to
starting using a more complete privilege separation approach, with a process
handling sensitive tasks (handling private keys, authentication), where we may
want to pass file descriptors between processes. how would that work on
windows?

anyway, getting mox to compile for windows doesn't mean it works properly on
windows. the largest issue: mox would normally open a file, rename or remove
it, and finally close it. this happens during message delivery. that doesn't
work on windows, the rename/remove would fail because the file is still open.
so this commit swaps many "remove" and "close" calls. renames are a longer
story: message delivery had two ways to deliver: with "consuming" the
(temporary) message file (which would rename it to its final destination), and
without consuming (by hardlinking the file, falling back to copying). the last
delivery to a recipient of a message (and the only one in the common case of a
single recipient) would consume the message, and the earlier recipients would
not.  during delivery, the already open message file was used, to parse the
message.  we still want to use that open message file, and the caller now stays
responsible for closing it, but we no longer try to rename (consume) the file.
we always hardlink (or copy) during delivery (this works on windows), and the
caller is responsible for closing and removing (in that order) the original
temporary file. this does cost one syscall more. but it makes the delivery code
(responsibilities) a bit simpler.

there is one more obvious issue: the file system path separator. mox already
used the "filepath" package to join paths in many places, but not everywhere.
and it still used strings with slashes for local file access. with this commit,
the code now uses filepath.FromSlash for path strings with slashes, uses
"filepath" in a few more places where it previously didn't. also switches from
"filepath" to regular "path" package when handling mailbox names in a few
places, because those always use forward slashes, regardless of local file
system conventions.  windows can handle forward slashes when opening files, so
test code that passes path strings with forward slashes straight to go stdlib
file i/o functions are left unchanged to reduce code churn. the regular
non-test code, or test code that uses path strings in places other than
standard i/o functions, does have the paths converted for consistent paths
(otherwise we would end up with paths with mixed forward/backward slashes in
log messages).

windows cannot dup a listening socket. for "mox localserve", it isn't
important, and we can work around the issue. the current approach for "mox
serve" (forking a process and passing file descriptors of listening sockets on
"privileged" ports) won't work on windows. perhaps it isn't needed on windows,
and any user can listen on "privileged" ports? that would be welcome.

on windows, os.Open cannot open a directory, so we cannot call Sync on it after
message delivery. a cursory internet search indicates that directories cannot
be synced on windows. the story is probably much more nuanced than that, with
long deep technical details/discussions/disagreement/confusion, like on unix.
for "mox localserve" we can get away with making syncdir a no-op.
2023-10-14 10:54:07 +02:00
Mechiel Lukkien
14d09bb308
format long multi-string dkim txt records for rsa 2048 as a mult-line record, enclosed in ()'s
more easily readable, though still long
2023-10-13 09:14:42 +02:00
Mechiel Lukkien
40040542f6
for generated dkim keys, use clearer file names
with ".rsa2048.privatekey.pkcs8.pem", instead of "rsakey.pkcs8.pem". "rsakey"
doesn't say if it is a public or private key.
2023-10-13 08:59:35 +02:00
Mechiel Lukkien
67fe88f431
change the autodiscover SRV record to point to the mail server hostname directly, not to a cname
srv targest shouldn't be cname's. bind was warning about it.
2023-10-13 08:51:02 +02:00
Mechiel Lukkien
850f4444d4
when suggesting DNS records, leave "IN" out
people will either paste the records in their zone file. in that case, the
records will inherit "IN" from earlier records, and there will always be one
record. if anyone uses a different class, their smart enough to know they need
to add IN manually.

plenty of people will add their records through some clunky web interface of
their dns operator. they probably won't even have the choice to set the class,
it'll always be IN.
2023-10-13 08:25:35 +02:00
Mechiel Lukkien
daa908e9f4
implement dnssec-awareness throughout code, and dane for incoming/outgoing mail delivery
the vendored dns resolver code is a copy of the go stdlib dns resolver, with
awareness of the "authentic data" (i.e. dnssec secure) added, as well as support
for enhanced dns errors, and looking up tlsa records (for dane). ideally it
would be upstreamed, but the chances seem slim.

dnssec-awareness is added to all packages, e.g. spf, dkim, dmarc, iprev. their
dnssec status is added to the Received message headers for incoming email.

but the main reason to add dnssec was for implementing dane. with dane, the
verification of tls certificates can be done through certificates/public keys
published in dns (in the tlsa records). this only makes sense (is trustworthy)
if those dns records can be verified to be authentic.

mox now applies dane to delivering messages over smtp. mox already implemented
mta-sts for webpki/pkix-verification of certificates against the (large) pool
of CA's, and still enforces those policies when present. but it now also checks
for dane records, and will verify those if present. if dane and mta-sts are
both absent, the regular opportunistic tls with starttls is still done. and the
fallback to plaintext is also still done.

mox also makes it easy to setup dane for incoming deliveries, so other servers
can deliver with dane tls certificate verification. the quickstart now
generates private keys that are used when requesting certificates with acme.
the private keys are pre-generated because they must be static and known during
setup, because their public keys must be published in tlsa records in dns.
autocert would generate private keys on its own, so had to be forked to add the
option to provide the private key when requesting a new certificate. hopefully
upstream will accept the change and we can drop the fork.

with this change, using the quickstart to setup a new mox instance, the checks
at internet.nl result in a 100% score, provided the domain is dnssec-signed and
the network doesn't have any issues.
2023-10-10 12:09:35 +02:00
Mechiel Lukkien
2b97c21f99
make setting up apple mail clients easier by providing .mobileconfig device management profiles
including showing a qr code to easily get the file on iphones.
the profile is currently in the "account" page.

idea by x8x in issue #65
2023-09-23 12:08:35 +02:00
Mechiel Lukkien
f4c20673ff
don't generate duplicate spf record if hostname is equal to domain name, e.g. postmaster@mail.domain.
the assumption has been that the hostname is something like mail.<domain>, when
setting up mox with the quickstart for user@<domain>. but users can use the
quickstart for postmaster@mail.<domain> as well.

for issue #46 by x8x, thanks for reporting!
2023-08-25 14:32:28 +02:00
Mechiel Lukkien
aebfd78a9f
implement accepting dmarc & tls reports for other domains
to accept reports for another domain, first add that domain to the config,
leaving all options empty except DMARC/TLSRPT in which you configure a Domain.

the suggested DNS DMARC/TLSRPT records will show the email address with
configured domain. for DMARC, the dnscheck functionality will verify that the
destination domain has opted in to receiving reports.

there is a new command-line subcommand "mox dmarc checkreportaddrs" that
verifies if dmarc reporting destination addresses have opted in to received
reports.

this also changes the suggested dns records (in quickstart, and through admin
pages and cli subcommand) to take into account whether DMARC and TLSRPT is
configured, and with which localpart/domain (previously it always printed
records as if reporting was enabled for the domain). and when generating the
suggested DNS records, the dmarc.Record and tlsrpt.Record code is used, with
proper uri-escaping.
2023-08-23 14:27:21 +02:00
Mechiel Lukkien
55d05c6bea
replace listener config option IPsNATed with NATIPs, and let autotls check NATIPs
NATIPs lists the public IPs, so we can still do the DNS checks on them. with
IPsNATed, we disabled the checks.

based on feedback by kikoreis in issue #52
2023-08-11 10:13:17 +02:00
Mechiel Lukkien
849b4ec9e9
add webmail
it was far down on the roadmap, but implemented earlier, because it's
interesting, and to help prepare for a jmap implementation. for jmap we need to
implement more client-like functionality than with just imap. internal data
structures need to change. jmap has lots of other requirements, so it's already
a big project. by implementing a webmail now, some of the required data
structure changes become clear and can be made now, so the later jmap
implementation can do things similarly to the webmail code. the webmail
frontend and webmail are written together, making their interface/api much
smaller and simpler than jmap.

one of the internal changes is that we now keep track of per-mailbox
total/unread/unseen/deleted message counts and mailbox sizes.  keeping this
data consistent after any change to the stored messages (through the code base)
is tricky, so mox now has a consistency check that verifies the counts are
correct, which runs only during tests, each time an internal account reference
is closed. we have a few more internal "changes" that are propagated for the
webmail frontend (that imap doesn't have a way to propagate on a connection),
like changes to the special-use flags on mailboxes, and used keywords in a
mailbox. more changes that will be required have revealed themselves while
implementing the webmail, and will be implemented next.

the webmail user interface is modeled after the mail clients i use or have
used: thunderbird, macos mail, mutt; and webmails i normally only use for
testing: gmail, proton, yahoo, outlook. a somewhat technical user is assumed,
but still the goal is to make this webmail client easy to use for everyone. the
user interface looks like most other mail clients: a list of mailboxes, a
search bar, a message list view, and message details. there is a top/bottom and
a left/right layout for the list/message view, default is automatic based on
screen size. the panes can be resized by the user. buttons for actions are just
text, not icons. clicking a button briefly shows the shortcut for the action in
the bottom right, helping with learning to operate quickly. any text that is
underdotted has a title attribute that causes more information to be displayed,
e.g. what a button does or a field is about. to highlight potential phishing
attempts, any text (anywhere in the webclient) that switches unicode "blocks"
(a rough approximation to (language) scripts) within a word is underlined
orange. multiple messages can be selected with familiar ui interaction:
clicking while holding control and/or shift keys.  keyboard navigation works
with arrows/page up/down and home/end keys, and also with a few basic vi-like
keys for list/message navigation. we prefer showing the text instead of
html (with inlined images only) version of a message. html messages are shown
in an iframe served from an endpoint with CSP headers to prevent dangerous
resources (scripts, external images) from being loaded. the html is also
sanitized, with javascript removed. a user can choose to load external
resources (e.g. images for tracking purposes).

the frontend is just (strict) typescript, no external frameworks. all
incoming/outgoing data is typechecked, both the api request parameters and
response types, and the data coming in over SSE. the types and checking code
are generated with sherpats, which uses the api definitions generated by
sherpadoc based on the Go code. so types from the backend are automatically
propagated to the frontend.  since there is no framework to automatically
propagate properties and rerender components, changes coming in over the SSE
connection are propagated explicitly with regular function calls.  the ui is
separated into "views", each with a "root" dom element that is added to the
visible document. these views have additional functions for getting changes
propagated, often resulting in the view updating its (internal) ui state (dom).
we keep the frontend compilation simple, it's just a few typescript files that
get compiled (combined and types stripped) into a single js file, no additional
runtime code needed or complicated build processes used.  the webmail is served
is served from a compressed, cachable html file that includes style and the
javascript, currently just over 225kb uncompressed, under 60kb compressed (not
minified, including comments). we include the generated js files in the
repository, to keep Go's easily buildable self-contained binaries.

authentication is basic http, as with the account and admin pages. most data
comes in over one long-term SSE connection to the backend. api requests signal
which mailbox/search/messages are requested over the SSE connection. fetching
individual messages, and making changes, are done through api calls. the
operations are similar to imap, so some code has been moved from package
imapserver to package store. the future jmap implementation will benefit from
these changes too. more functionality will probably be moved to the store
package in the future.

the quickstart enables webmail on the internal listener by default (for new
installs). users can enable it on the public listener if they want to. mox
localserve enables it too. to enable webmail on existing installs, add settings
like the following to the listeners in mox.conf, similar to AccountHTTP(S):

	WebmailHTTP:
		Enabled: true
	WebmailHTTPS:
		Enabled: true

special thanks to liesbeth, gerben, andrii for early user feedback.

there is plenty still to do, see the list at the top of webmail/webmail.ts.
feedback welcome as always.
2023-08-07 21:57:03 +02:00
Mechiel Lukkien
03c3f56a59
add basic tests for the ctl subcommands, and fix two small bugs
this doesn't really test the output of the ctl commands, just that they succeed
without error. better than nothing...

testing found two small bugs, that are not an issue in practice:

1. we were ack'ing streamed data from the other side of the ctl connection
before having read it. when there is no buffer space on the connection (always
the case for net.Pipe) that would cause a deadlock. only actually happened
during the new tests.

2. the generated dkim keys are relatively to the directory of the dynamic
config file. mox looked it up relative to the directory of the _static_ config
file at startup. this directory is typicaly the same. users would have noticed
if they had triggered this.
2023-07-02 14:18:50 +02:00
Mechiel Lukkien
8096441f67
new feature: when delivering messages from the queue, make it possible to use a "transport"
the default transport is still just "direct delivery", where we connect to the
destination domain's MX servers.

other transports are:

- regular smtp without authentication, this is relaying to a smarthost.
- submission with authentication, e.g. to a third party email sending service.
- direct delivery, but with with connections going through a socks proxy. this
  can be helpful if your ip is blocked, you need to get email out, and you have
  another IP that isn't blocked.

keep in mind that for all of the above, appropriate SPF/DKIM settings have to
be configured. the "dnscheck" for a domain does a check for any SOCKS IP in the
SPF record. SPF for smtp/submission (ranges? includes?) and any DKIM
requirements cannot really be checked.

which transport is used can be configured through routes. routes can be set on
an account, a domain, or globally. the routes are evaluated in that order, with
the first match selecting the transport. these routes are evaluated for each
delivery attempt. common selection criteria are recipient domain and sender
domain, but also which delivery attempt this is. you could configured mox to
attempt sending through a 3rd party from the 4th attempt onwards.

routes and transports are optional. if no route matches, or an empty/zero
transport is selected, normal direct delivery is done.

we could already "submit" emails with 3rd party accounts with "sendmail". but
we now support more SASL authentication mechanisms with SMTP (not only PLAIN,
but also SCRAM-SHA-256, SCRAM-SHA-1 and CRAM-MD5), which sendmail now also
supports. sendmail will use the most secure mechanism supported by the server,
or the explicitly configured mechanism.

for issue #36 by dmikushin. also based on earlier discussion on hackernews.
2023-06-16 18:57:05 +02:00
Mechiel Lukkien
c1753b369d
in smtpserver, accept delivery to postmaster@<hostname>, and also postmaster@ addresses for domains that don't have a postmaster address configured. 2023-04-24 12:04:46 +02:00
Mechiel Lukkien
b571dd4b28
implement a catchall address for a domain
by specifying a "destination" in an account that is just "@" followed by the
domain, e.g. "@example.org". messages are only delivered to the catchall
address when no regular destination matches (taking the per-domain
catchall-separator and case-sensisitivity into account).

for issue #18
2023-03-29 21:11:43 +02:00
Mechiel Lukkien
51ad345dbb
refuse to add an address when its localpart contains the domains catchall separator, or when its canonicalized address (e.g. lower cased when case-insensitive) is already present, and check at startup as well
such configurations are certainly errors, but were silently accepted and highly
likely not doing what you may have hoped. i suspect no one has configured mox
this way.
2023-03-29 20:58:50 +02:00
Mechiel Lukkien
9b57c69c1c
implement limits on outgoing messages for an account
by default 1000 messages per day, and to max 200 first-time receivers.
i don't think a person would reach those limits. a compromised account abused
by spammers could easily reach that limit. this prevents further damage.

the error message you will get is quite clear, pointing to the configuration
parameter that should be changed.
2023-03-29 09:36:06 +02:00
Mechiel Lukkien
2c07645ab4
deprecate having only localparts in an Account's Destinations, it should always be a full email address
current behaviour isn't intuitive. it's not great to have to attempt parsing
the strings as both localpart and email address. so we deprecate the
localpart-only behaviour. when we load the config file, and it has
localpart-only Destinations keys, we'll change them to full addresses in
memory. when an admin causes a write of domains.conf, it'll automatically be
fixed. we log an error with a deprecated notice for each localpart-only
destinations key.

sometime in the future, we can remove the old localpart-only destination
support. will be in the release notes then.

also start keeping track of update notes that need to make it in the release
notes of the next release.

for issue #18
2023-03-09 22:13:56 +01:00
Mechiel Lukkien
e6df84a8de
add config field "IPsNATed" to listener, indicating the IPs are not the actual public IPs but are NATed, to skip a few DNS checks
the dns check was returning errors that could not be fixed with that setup,
which makes the checks much less useful.

for issue #17
2023-03-09 15:24:06 +01:00
Mechiel Lukkien
6abee87aa3
improve webserver, add domain redirects (aliases), add tests and admin page ui to manage the config
- make builtin http handlers serve on specific domains, such as for mta-sts, so
  e.g. /.well-known/mta-sts.txt isn't served on all domains.
- add logging of a few more fields in access logging.
- small tweaks/bug fixes in webserver request handling.
- add config option for redirecting entire domains to another (common enough).
- split httpserver metric into two: one for duration until writing header (i.e.
  performance of server), another for duration until full response is sent to
  client (i.e. performance as perceived by users).
- add admin ui, a new page for managing the configs. after making changes
  and hitting "save", the changes take effect immediately. the page itself
  doesn't look very well-designed (many input fields, makes it look messy). i
  have an idea to improve it (explained in admin.html as todo) by making the
  layout look just like the config file. not urgent though.

i've already changed my websites/webapps over.

the idea of adding a webserver is to take away a (the) reason for folks to want
to complicate their mox setup by running an other webserver on the same machine.
i think the current webserver implementation can already serve most common use
cases. with a few more tweaks (feedback needed!) we should be able to get to 95%
of the use cases. the reverse proxy can take care of the remaining 5%.
nevertheless, a next step is still to change the quickstart to make it easier
for folks to run with an existing webserver, with existing tls certs/keys.
that's how this relates to issue #5.
2023-03-02 18:15:54 +01:00
Mechiel Lukkien
e2e2c71212
minor tweaks to suggested dns records 2023-02-27 15:04:32 +01:00
Mechiel Lukkien
92e018e463
change mox to start as root, bind to network sockets, then drop to regular unprivileged mox user
makes it easier to run on bsd's, where you cannot (easily?) let non-root users
bind to ports <1024. starting as root also paves the way for future improvements
with privilege separation.

unfortunately, this requires changes to how you start mox. though mox will help
by automatically fix up dir/file permissions/ownership.

if you start mox from the systemd unit file, you should update it so it starts
as root and adds a few additional capabilities:

        # first update the mox binary, then, as root:
        ./mox config printservice >mox.service
        systemctl daemon-reload
        systemctl restart mox
        journalctl -f -u mox &
        # you should see mox start up, with messages about fixing permissions on dirs/files.

if you used the recommended config/ and data/ directory, in a directory just for
mox, and with the mox user called "mox", this should be enough.

if you don't want mox to modify dir/file permissions, set "NoFixPermissions:
true" in mox.conf.

if you named the mox user something else than mox, e.g. "_mox", add "User: _mox"
to mox.conf.

if you created a shared service user as originally suggested, you may want to
get rid of that as it is no longer useful and may get in the way. e.g. if you
had /home/service/mox with a "service" user, that service user can no longer
access any files: only mox and root can.

this also adds scripts for building mox docker images for alpine-supported
platforms.

the "restart" subcommand has been removed. it wasn't all that useful and got in
the way.

and another change: when adding a domain while mtasts isn't enabled, don't add
the per-domain mtasts config, as it would cause failure to add the domain.

based on report from setting up mox on openbsd from mteege.
and based on issue #3. thanks for the feedback!
2023-02-27 12:19:55 +01:00
Mechiel Lukkien
5c33640aea
consistently use log.Check for logging errors that "should not happen", don't influence application flow
sooner or later, someone will notice one of these messages, which will lead us
to a bug.
2023-02-16 13:22:00 +01:00
Mechiel Lukkien
707d3a3fa0
store rejects for 14 days, and don't keep them as neutral by default so they won't cause outright rejects for repeated delivery attempts of spam messages
the previous default, marking the messages as junk had the interesting effect
of training the junk filter. rejecting could have been the result of the
sending IP being in the DNSBL. so the DNSBL helped to automatically train the
junk filter. perhaps we can keep that in the future and just not take messages
from the rejects mailbox into account when evaluating the reputation for
incoming deliveries.
2023-02-13 10:47:20 +01:00
Mechiel Lukkien
bf04fb8a1a
improve training of junk filter
before, we used heuristics to decide when to train/untrain a message as junk or
nonjunk: the message had to be seen, be in certain mailboxes. then if a message
was marked as junk, it was junk. and otherwise it was nonjunk. this wasn't good
enough: you may want to keep some messages around as neither junk or nonjunk.
and that wasn't possible.

ideally, we would just look at the imap $Junk and $NotJunk flags. the problem
is that mail clients don't set these flags, or don't make it easy. thunderbird
can set the flags based on its own bayesian filter. it has a shortcut for
marking Junk and moving it to the junk folder (good), but the counterpart of
notjunk only marks a message as notjunk without showing in the UI that it was
marked as notjunk. there is also no "move and mark as notjunk" mechanism. e.g.
"archive" does not mark a message as notjunk. ios mail and mutt don't appear to
have any way to see or change the $Junk and $NotJunk flags.

what email clients do have is the ability to move messages to other
mailboxes/folders. so mox now has a mechanism that allows you to configure
mailboxes that automatically set $Junk or $NotJunk (or clear both) when a
message is moved/copied/delivered to that folder. e.g. a mailbox called junk or
spam or rejects marks its messags as junk. inbox, postmaster, dmarc, tlsrpt,
neutral* mark their messages as neither junk or notjunk. other folders mark
their messages as notjunk. e.g. list/*, archive. this functionality is
optional, but enabled with the quickstart and for new accounts.

also, mox now keeps track of the previous training of a message and will only
untrain/train if needed. before, there probably have been duplicate or missing
(un)trainings.

this also includes a new subcommand "retrain" to recreate the junkfilter for an
account. you should run it after updating to this version. and you should
probably also modify your account config to include the AutomaticJunkFlags.
2023-02-11 23:00:12 +01:00
Mechiel Lukkien
d48d19b840
in account web page, allow user to configure rulesets for delivery
for example, by matching incoming messags on smtp mail from, verified domains
(spf/dkim), headers. then delivering to a configured mailbox. for mailing
lists, if a verified domain matches, regular spam checks can be skipped.

this was already possible by editing the configuration file, but only admins
can edit that file. now users can manage their own rulesets.
2023-02-10 23:47:19 +01:00
Mechiel Lukkien
9792158324
improve quickstart and readme for better first-time experience
- make the example commands in the readme more likely to succeed, especially
  for people who are not familiar with go and its toolchain.
- improve probability that the correct configuration is generated, especially
  the hostname. previously, if the quickstart email address was "some.domain",
  and the machine where you ran the quickstart was "myhost", the hostname used
  for the configuration was assumed to be "myhost.some.domain". but this is often
  not correct, especially when configuring mox to serve mail on a subdomain of an
  existing domain. mox will now try to determine the host name by a reverse
  lookup of the public ips it found. and it will warn if there are no/multiple
  candidates.

based on feedback from erik dubbelboer, thanks!
2023-02-05 21:25:48 +01:00
Mechiel Lukkien
c21b8c0d54
add reverse ip checks during quickstart and in "check dns" admin page/subcommand
- and don't have a global variable "d" in the big checkDomain function in http/admin.go.
- and set loglevel from command-line flag again after loading the config file, for all subcommands except "serve".
2023-02-03 15:54:34 +01:00
Mechiel Lukkien
cb229cb6cf
mox! 2023-01-30 14:27:06 +01:00