// Port returns port if non-zero, and fallback otherwise.
funcPort(port,fallbackint)int{
ifport==0{
returnfallback
}
returnport
}
// Static is a parsed form of the mox.conf configuration file, before converting it
// into a mox.Config after additional processing.
typeStaticstruct{
DataDirstring`sconf-doc:"Directory where all data is stored, e.g. queue, accounts and messages, ACME TLS certs/keys. If this is a relative path, it is relative to the directory of mox.conf."`
LogLevelstring`sconf-doc:"Default log level, one of: error, info, debug, trace, traceauth, tracedata. Trace logs SMTP and IMAP protocol transcripts, with traceauth also messages with passwords, and tracedata on top of that also the full data exchanges (full messages), which can be a large amount of data."`
Userstring`sconf:"optional" sconf-doc:"User to switch to after binding to all sockets as root. Default: mox. If the value is not a known user, it is parsed as integer and used as uid and gid."`
NoFixPermissionsbool`sconf:"optional" sconf-doc:"If true, do not automatically fix file permissions when starting up. By default, mox will ensure reasonable owner/permissions on the working, data and config directories (and files), and mox binary (if present)."`
Hostnamestring`sconf-doc:"Full hostname of system, e.g. mail.<domain>"`
HostnameDomaindns.Domain`sconf:"-" json:"-"`// Parsed form of hostname.
CheckUpdatesbool`sconf:"optional" sconf-doc:"If enabled, a single DNS TXT lookup of _updates.xmox.nl is done every 24h to check for a new release. Each time a new release is found, a changelog is fetched from https://updates.xmox.nl and delivered to the postmaster mailbox."`
Pedanticbool`sconf:"optional" sconf-doc:"In pedantic mode protocol violations (that happen in the wild) for SMTP/IMAP/etc result in errors instead of accepting such behaviour."`
}`sconf:"optional" sconf-doc:"Global TLS configuration, e.g. for additional Certificate Authorities. Used for outgoing SMTP connections, HTTPS requests."`
ACMEmap[string]ACME`sconf:"optional" sconf-doc:"Automatic TLS configuration with ACME, e.g. through Let's Encrypt. The key is a name referenced in TLS configs, e.g. letsencrypt."`
AdminPasswordFilestring`sconf:"optional" sconf-doc:"File containing hash of admin password, for authentication in the web admin pages (if enabled)."`
Listenersmap[string]Listener`sconf-doc:"Listeners are groups of IP addresses and services enabled on those IP addresses, such as SMTP/IMAP or internal endpoints for administration or Prometheus metrics. All listeners with SMTP/IMAP services enabled will serve all configured domains. If the listener is named 'public', it will get a few helpful additional configuration checks, for acme automatic tls certificates and monitoring of ips in dnsbls if those are configured."`
}`sconf-doc:"Destination for emails delivered to postmaster addresses: a plain 'postmaster' without domain, 'postmaster@<hostname>' (also for each listener with SMTP enabled), and as fallback for each domain without explicitly configured postmaster destination."`
DefaultMailboxes[]string`sconf:"optional" sconf-doc:"Mailboxes to create when adding an account. Inbox is always created. If no mailboxes are specified, the following are automatically created: Sent, Archive, Trash, Drafts and Junk."`
// All IPs that were explicitly listen on for external SMTP. Only set when there
Domainsmap[string]Domain`sconf-doc:"Domains for which email is accepted. For internationalized domains, use their IDNA names in UTF-8."`
Accountsmap[string]Account`sconf-doc:"Accounts to which email can be delivered. An account can accept email for multiple domains, for multiple localparts, and deliver to multiple mailboxes."`
WebDomainRedirectsmap[string]string`sconf:"optional" sconf-doc:"Redirect all requests from domain (key) to domain (value). Always redirects to HTTPS. For plain HTTP redirects, use a WebHandler with a WebRedirect."`
WebHandlers[]WebHandler`sconf:"optional" sconf-doc:"Handle webserver requests by serving static files, redirecting or reverse-proxying HTTP(s). The first matching WebHandler will handle the request. Built-in handlers, e.g. for account, admin, autoconfig and mta-sts always run first. If no handler matches, the response status code is file not found (404). If functionality you need is missng, simply forward the requests to an application that can provide the needed functionality."`
DirectoryURLstring`sconf-doc:"For letsencrypt, use https://acme-v02.api.letsencrypt.org/directory."`
RenewBeforetime.Duration`sconf:"optional" sconf-doc:"How long before expiration to renew the certificate. Default is 30 days."`
ContactEmailstring`sconf-doc:"Email address to register at ACME provider. The provider can email you when certificates are about to expire. If you configure an address for which email is delivered by this server, keep in mind that TLS misconfigurations could result in such notification emails not arriving."`
Portint`sconf:"optional" sconf-doc:"TLS port for ACME validation, 443 by default. You should only override this if you cannot listen on port 443 directly. ACME will make requests to port 443, so you'll have to add an external mechanism to get the connection here, e.g. by configuring port forwarding."`
IPs[]string`sconf-doc:"Use 0.0.0.0 to listen on all IPv4 and/or :: to listen on all IPv6 addresses, but it is better to explicitly specify the IPs you want to use for email, as mox will make sure outgoing connections will only be made from one of those IPs."`
IPsNATedbool`sconf:"optional" sconf-doc:"Set this if the specified IPs are not the public IPs, but are NATed. This makes the DNS check skip a few checks related to IPs, such as for iprev, mx, spf, autoconfig, autodiscover."`
Hostnamestring`sconf:"optional" sconf-doc:"If empty, the config global Hostname is used."`
HostnameDomaindns.Domain`sconf:"-" json:"-"`// Set when parsing config.
TLS*TLS`sconf:"optional" sconf-doc:"For SMTP/IMAP STARTTLS, direct TLS and HTTPS connections."`
SMTPMaxMessageSizeint64`sconf:"optional" sconf-doc:"Maximum size in bytes accepted incoming and outgoing messages. Default is 100MB."`
SMTPstruct{
Enabledbool
Portint`sconf:"optional" sconf-doc:"Default 25."`
NoSTARTTLSbool`sconf:"optional" sconf-doc:"Do not offer STARTTLS to secure the connection. Not recommended."`
RequireSTARTTLSbool`sconf:"optional" sconf-doc:"Do not accept incoming messages if STARTTLS is not active. Can be used in combination with a strict MTA-STS policy. A remote SMTP server may not support TLS and may not be able to deliver messages."`
DNSBLs[]string`sconf:"optional" sconf-doc:"Addresses of DNS block lists for incoming messages. Block lists are only consulted for connections/messages without enough reputation to make an accept/reject decision. This prevents sending IPs of all communications to the block list provider. If any of the listed DNSBLs contains a requested IP address, the message is rejected as spam. The DNSBLs are checked for healthiness before use, at most once per 4 hours. Example DNSBLs: sbl.spamhaus.org, bl.spamcop.net"`
NoRequireSTARTTLSbool`sconf:"optional" sconf-doc:"Do not require STARTTLS. Since users must login, this means password may be sent without encryption. Not recommended."`
}`sconf:"optional" sconf-doc:"SMTP for submitting email, e.g. by email applications. Starts out in plain text, can be upgraded to TLS with the STARTTLS command. Prefer using Submissions which is always a TLS connection."`
NoRequireSTARTTLSbool`sconf:"optional" sconf-doc:"Enable this only when the connection is otherwise encrypted (e.g. through a VPN)."`
}`sconf:"optional" sconf-doc:"IMAP for reading email, by email applications. Starts out in plain text, can be upgraded to TLS with the STARTTLS command. Prefer using IMAPS instead which is always a TLS connection."`
}`sconf:"optional" sconf-doc:"Account web interface, for email users wanting to change their accounts, e.g. set new password, set new delivery rulesets. Served at /."`
Pathstring`sconf:"optional" sconf-doc:"Path to serve admin requests on, e.g. /moxadmin/. Useful if domain serves other resources. Default is /admin/."`
}`sconf:"optional" sconf-doc:"Admin web interface, for managing domains, accounts, etc. Served at /admin/. Preferably only enable on non-public IPs. Hint: use 'ssh -L 8080:localhost:80 you@yourmachine' and open http://localhost:8080/admin/, or set up a tunnel (e.g. WireGuard) and add its IP to the mox 'internal' listener."`
Pathstring`sconf:"optional" sconf-doc:"Path to serve admin requests on, e.g. /moxadmin/. Useful if domain serves other resources. Default is /admin/."`
Portint`sconf:"optional" sconf-doc:"TLS port, 443 by default. You should only override this if you cannot listen on port 443 directly. Autoconfig requests will be made to port 443, so you'll have to add an external mechanism to get the connection here, e.g. by configuring port forwarding."`
NonTLSbool`sconf:"optional" sconf-doc:"If set, plain HTTP instead of HTTPS is spoken on the configured port. Can be useful when the autoconfig domain is reverse proxied."`
}`sconf:"optional" sconf-doc:"Serve autoconfiguration/autodiscovery to simplify configuring email applications, will use port 443. Requires a TLS config."`
Portint`sconf:"optional" sconf-doc:"TLS port, 443 by default. You should only override this if you cannot listen on port 443 directly. MTA-STS requests will be made to port 443, so you'll have to add an external mechanism to get the connection here, e.g. by configuring port forwarding."`
NonTLSbool`sconf:"optional" sconf-doc:"If set, plain HTTP instead of HTTPS is spoken on the configured port. Can be useful when the mta-sts domain is reverse proxied."`
Portint`sconf:"optional" sconf-doc:"Port for plain HTTP (non-TLS) webserver."`
}`sconf:"optional" sconf-doc:"All configured WebHandlers will serve on an enabled listener."`
WebserverHTTPSstruct{
Enabledbool
Portint`sconf:"optional" sconf-doc:"Port for HTTPS webserver."`
}`sconf:"optional" sconf-doc:"All configured WebHandlers will serve on an enabled listener. Either ACME must be configured, or for each WebHandler domain a TLS certificate must be configured."`
Descriptionstring`sconf:"optional" sconf-doc:"Free-form description of domain."`
LocalpartCatchallSeparatorstring`sconf:"optional" sconf-doc:"If not empty, only the string before the separator is used to for email delivery decisions. For example, if set to \"+\", you+anything@example.com will be delivered to you@example.com."`
LocalpartCaseSensitivebool`sconf:"optional" sconf-doc:"If set, upper/lower case is relevant for email delivery."`
DKIMDKIM`sconf:"optional" sconf-doc:"With DKIM signing, a domain is taking responsibility for (content of) emails it sends, letting receiving mail servers build up a (hopefully positive) reputation of the domain, which can help with mail delivery."`
DMARC*DMARC`sconf:"optional" sconf-doc:"With DMARC, a domain publishes, in DNS, a policy on how other mail servers should handle incoming messages with the From-header matching this domain and/or subdomain (depending on the configured alignment). Receiving mail servers use this to build up a reputation of this domain, which can help with mail delivery. A domain can also publish an email address to which reports about DMARC verification results can be sent by verifying mail servers, useful for monitoring. Incoming DMARC reports are automatically parsed, validated, added to metrics and stored in the reporting database for later display in the admin web pages."`
MTASTS*MTASTS`sconf:"optional" sconf-doc:"With MTA-STS a domain publishes, in DNS, presence of a policy for using/requiring TLS for SMTP connections. The policy is served over HTTPS."`
TLSRPT*TLSRPT`sconf:"optional" sconf-doc:"With TLSRPT a domain specifies in DNS where reports about encountered SMTP TLS behaviour should be sent. Useful for monitoring. Incoming TLS reports are automatically parsed, validated, added to metrics and stored in the reporting database for later display in the admin web pages."`
Domaindns.Domain`sconf:"-" json:"-"`
}
typeDMARCstruct{
Localpartstring`sconf-doc:"Address-part before the @ that accepts DMARC reports. Must be non-internationalized. Recommended value: dmarc-reports."`
Accountstring`sconf-doc:"Account to deliver to."`
Mailboxstring`sconf-doc:"Mailbox to deliver to, e.g. DMARC."`
ParsedLocalpartsmtp.Localpart`sconf:"-"`
}
typeMTASTSstruct{
PolicyIDstring`sconf-doc:"Policies are versioned. The version must be specified in the DNS record. If you change a policy, first change it in mox, then update the DNS record."`
Modemtasts.Mode`sconf-doc:"testing, enforce or none. If set to enforce, a remote SMTP server will not deliver email to us if it cannot make a TLS connection."`
MaxAgetime.Duration`sconf-doc:"How long a remote mail server is allowed to cache a policy. Typically 1 or several weeks."`
MX[]string`sconf:"optional" sconf-doc:"List of server names allowed for SMTP. If empty, the configured hostname is set. Host names can contain a wildcard (*) as a leading label (matching a single label, e.g. *.example matches host.example, not sub.host.example)."`
// todo: parse mx as valid mtasts.Policy.MX, with dns.ParseDomain but taking wildcard into account
}
typeTLSRPTstruct{
Localpartstring`sconf-doc:"Address-part before the @ that accepts TLSRPT reports. Recommended value: tls-reports."`
Accountstring`sconf-doc:"Account to deliver to."`
Mailboxstring`sconf-doc:"Mailbox to deliver to, e.g. TLSRPT."`
ParsedLocalpartsmtp.Localpart`sconf:"-"`
}
typeSelectorstruct{
Hashstring`sconf:"optional" sconf-doc:"sha256 (default) or (older, not recommended) sha1"`
HashEffectivestring`sconf:"-"`
Canonicalizationstruct{
HeaderRelaxedbool`sconf-doc:"If set, some modifications to the headers (mostly whitespace) are allowed."`
BodyRelaxedbool`sconf-doc:"If set, some whitespace modifications to the message body are allowed."`
}`sconf:"optional"`
Headers[]string`sconf:"optional" sconf-doc:"Headers to sign with DKIM. If empty, a reasonable default set of headers is selected."`
HeadersEffective[]string`sconf:"-"`
DontSealHeadersbool`sconf:"optional" sconf-doc:"If set, don't prevent duplicate headers from being added. Not recommended."`
Expirationstring`sconf:"optional" sconf-doc:"Period a signature is valid after signing, as duration, e.g. 72h. The period should be enough for delivery at the final destination, potentially with several hops/relays. In the order of days at least."`
PrivateKeyFilestring`sconf-doc:"Either an RSA or ed25519 private key file in PKCS8 PEM form."`
ExpirationSecondsint`sconf:"-" json:"-"`// Parsed from Expiration.
Keycrypto.Signer`sconf:"-" json:"-"`// As parsed with x509.ParsePKCS8PrivateKey.
Domaindns.Domain`sconf:"-" json:"-"`// Of selector only, not FQDN.
}
typeDKIMstruct{
Selectorsmap[string]Selector`sconf-doc:"Emails can be DKIM signed. Config parameters are per selector. A DNS record must be created for each selector. Add the name to Sign to use the selector for signing messages."`
Sign[]string`sconf:"optional" sconf-doc:"List of selectors that emails will be signed with."`
Domainstring`sconf-doc:"Default domain for account. Deprecated behaviour: If a destination is not a full address but only a localpart, this domain is added to form a full address."`
Destinationsmap[string]Destination`sconf-doc:"Destinations, keys are email addresses (with IDNA domains). If the address is of the form '@domain', i.e. with localpart missing, it serves as a catchall for the domain, matching all messages that are not explicitly configured. Deprecated behaviour: If the address is not a full address but a localpart, it is combined with Domain to form a full address."`
Periodtime.Duration`sconf-doc:"How long unique values are accepted after generating, e.g. 12h."`// todo: have a reasonable default for this?
}`sconf:"optional" sconf-doc:"If configured, messages classified as weakly spam are rejected with instructions to retry delivery, but this time with a signed token added to the subject. During the next delivery attempt, the signed token will bypass the spam filter. Messages with a clear spam signal, such as a known bad reputation, are rejected/delayed without a signed token."`
RejectsMailboxstring`sconf:"optional" sconf-doc:"Mail that looks like spam will be rejected, but a copy can be stored temporarily in a mailbox, e.g. Rejects. If mail isn't coming in when you expect, you can look there. The mail still isn't accepted, so the remote mail server may retry (hopefully, if legitimate), or give up (hopefully, if indeed a spammer). Messages are automatically removed from this mailbox, so do not set it to a mailbox that has messages you want to keep."`
Enabledbool`sconf-doc:"If enabled, flags will be set automatically if they match a regular expression below. When two of the three mailbox regular expressions are set, the remaining one will match all unmatched messages. Messages are matched in the order specified and the search stops on the first match. Mailboxes are lowercased before matching."`
NeutralMailboxRegexpstring`sconf:"optional" sconf-doc:"Example: ^(inbox|neutral|postmaster|dmarc|tlsrpt|rejects), and you may wish to add trash depending on how you use it, or leave this empty."`
NotJunkMailboxRegexpstring`sconf:"optional" sconf-doc:"Example: .* or an empty string."`
}`sconf:"optional" sconf-doc:"Automatically set $Junk and $NotJunk flags based on mailbox messages are delivered/moved/copied to. Email clients typically have too limited functionality to conveniently set these flags, especially $NonJunk, but they can all move messages to a different mailbox, so this helps them."`
JunkFilter*JunkFilter`sconf:"optional" sconf-doc:"Content-based filtering, using the junk-status of individual messages to rank words in such messages as spam or ham. It is recommended you always set the applicable (non)-junk status on messages, and that you do not empty your Trash because those messages contain valuable ham/spam training information."`// todo: sane defaults for junkfilter
MaxOutgoingMessagesPerDayint`sconf:"optional" sconf-doc:"Maximum number of outgoing messages for this account in a 24 hour window. This limits the damage to recipients and the reputation of this mail server in case of account compromise. Default 1000."`
MaxFirstTimeRecipientsPerDayint`sconf:"optional" sconf-doc:"Maximum number of first-time recipients in outgoing messages for this account in a 24 hour window. This limits the damage to recipients and the reputation of this mail server in case of account compromise. Default 200."`
Thresholdfloat64`sconf-doc:"Approximate spaminess score between 0 and 1 above which emails are rejected as spam. Each delivery attempt adds a little noise to make it slightly harder for spammers to identify words that strongly indicate non-spaminess and use it to bypass the filter. E.g. 0.95."`
junk.Params
}
typeDestinationstruct{
Mailboxstring`sconf:"optional" sconf-doc:"Mailbox to deliver to if none of Rulesets match. Default: Inbox."`
Rulesets[]Ruleset`sconf:"optional" sconf-doc:"Delivery rules based on message and SMTP transaction. You may want to match each mailing list by SMTP MailFrom address, VerifiedDomain and/or List-ID header (typically <listname.example.org> if the list address is listname@example.org), delivering them to their own mailbox."`
SMTPMailFromRegexpstring`sconf:"optional" sconf-doc:"Matches if this regular expression matches (a substring of) the SMTP MAIL FROM address (not the message From-header). E.g. user@example.org."`
VerifiedDomainstring`sconf:"optional" sconf-doc:"Matches if this domain matches an SPF- and/or DKIM-verified (sub)domain."`
HeadersRegexpmap[string]string`sconf:"optional" sconf-doc:"Matches if these header field/value regular expressions all match (substrings of) the message headers. Header fields and valuees are converted to lower case before matching. Whitespace is trimmed from the value before matching. A header field can occur multiple times in a message, only one instance has to match. For mailing lists, you could match on ^list-id$ with the value typically the mailing list address in angled brackets with @ replaced with a dot, e.g. <name\\.lists\\.example\\.org>."`
ListAllowDomainstring`sconf:"optional" sconf-doc:"Influence the spam filtering, this does not change whether this ruleset applies to a message. If this domain matches an SPF- and/or DKIM-verified (sub)domain, the message is accepted without further spam checks, such as a junk filter or DMARC reject evaluation. DMARC rejects should not apply for mailing lists that are not configured to rewrite the From-header of messages that don't have a passing DKIM signature of the From-domain. Otherwise, by rejecting messages, you may be automatically unsubscribed from the mailing list. The assumption is that mailing lists do their own spam filtering/moderation."`
LogNamestring`sconf:"optional" sconf-doc:"Name to use in logging and metrics."`
Domainstring`sconf-doc:"Both Domain and PathRegexp must match for this WebHandler to match a request. Exactly one of WebStatic, WebRedirect, WebForward must be set."`
PathRegexpstring`sconf-doc:"Regular expression matched against request path, must always start with ^ to ensure matching from the start of the path. The matching prefix can optionally be stripped by WebForward. The regular expression does not have to end with $."`
DontRedirectPlainHTTPbool`sconf:"optional" sconf-doc:"If set, plain HTTP requests are not automatically permanently redirected (308) to HTTPS. If you don't have a HTTPS webserver configured, set this to true."`
StripPrefixstring`sconf:"optional" sconf-doc:"Path to strip from the request URL before evaluating to a local path. If the requested URL path does not start with this prefix and ContinueNotFound it is considered non-matching and next WebHandlers are tried. If ContinueNotFound is not set, a file not found (404) is returned in that case."`
Rootstring`sconf-doc:"Directory to serve files from for this handler. Keep in mind that relative paths are relative to the working directory of mox."`
ListFilesbool`sconf:"optional" sconf-doc:"If set, and a directory is requested, and no index.html is present that can be served, a file listing is returned. Results in 403 if ListFiles is not set. If a directory is requested and the URL does not end with a slash, the response is a redirect to the path with trailing slash."`
ContinueNotFoundbool`sconf:"optional" sconf-doc:"If a requested URL does not exist, don't return a file not found (404) response, but consider this handler non-matching and continue attempts to serve with later WebHandlers, which may be a reverse proxy generating dynamic content, possibly even writing a static file for a next request to serve statically. If ContinueNotFound is set, HTTP requests other than GET and HEAD do not match. This mechanism can be used to implement the equivalent of 'try_files' in other webservers."`
ResponseHeadersmap[string]string`sconf:"optional" sconf-doc:"Headers to add to the response. Useful for cache-control, content-type, etc. By default, Content-Type headers are automatically added for recognized file types, unless added explicitly through this setting. For directory listings, a content-type header is skipped."`
BaseURLstring`sconf:"optional" sconf-doc:"Base URL to redirect to. The path must be empty and will be replaced, either by the request URL path, or by OrigPathRegexp/ReplacePath. Scheme, host, port and fragment stay intact, and query strings are combined. If empty, the response redirects to a different path through OrigPathRegexp and ReplacePath, which must then be set. Use a URL without scheme to redirect without changing the protocol, e.g. //newdomain/. If a redirect would send a request to a URL with the same scheme, host and path, the WebRedirect does not match so a next WebHandler can be tried. This can be used to redirect all plain http traffic to https."`
OrigPathRegexpstring`sconf:"optional" sconf-doc:"Regular expression for matching path. If set and path does not match, a 404 is returned. The HTTP path used for matching always starts with a slash."`
ReplacePathstring`sconf:"optional" sconf-doc:"Replacement path for destination URL based on OrigPathRegexp. Implemented with Go's Regexp.ReplaceAllString: $1 is replaced with the text of the first submatch, etc. If both OrigPathRegexp and ReplacePath are empty, BaseURL must be set and all paths are redirected unaltered."`
StatusCodeint`sconf:"optional" sconf-doc:"Status code to use in redirect, e.g. 307. By default, a permanent redirect (308) is returned."`
URLstring`sconf-doc:"URL to forward HTTP requests to, e.g. http://127.0.0.1:8123/base. If StripPath is false the full request path is added to the URL. Host headers are sent unmodified. New X-Forwarded-{For,Host,Proto} headers are set. Any query string in the URL is ignored. Requests are made using Go's net/http.DefaultTransport that takes environment variables HTTP_PROXY and HTTPS_PROXY into account. Websocket connections are forwarded and data is copied between client and backend without looking at the framing. The websocket 'version' and 'key'/'accept' headers are verified during the handshake, but other websocket headers, including 'origin', 'protocol' and 'extensions' headers, are not inspected and the backend is responsible for verifying/interpreting them."`