in DSNs, add a References header pointing to the message with deliverability issues

so mail user agents will show DSNs threaded/grouped with the original message.
we store the MessageID in the message queue, so we have the value within reach
when we need it.

i saw a references header in a DSN from gmail on a test account. makes sense to me.
This commit is contained in:
Mechiel Lukkien 2023-07-23 17:56:39 +02:00
parent c5747bd656
commit dcb0f0a82c
No known key found for this signature in database
8 changed files with 50 additions and 27 deletions

View file

@ -45,6 +45,13 @@ type Message struct {
// Message subject header, e.g. describing mail delivery failure.
Subject string
// Set when message is composed.
MessageID string
// References header, with Message-ID of original message this DSN is about. So
// mail user-agents will thread the DSN with the original message.
References string
// Human-readable text explaining the failure. Line endings should be
// bare newlines, not \r\n. They are converted to \r\n when composing.
TextBody string
@ -158,7 +165,11 @@ func (m *Message) Compose(log *mlog.Log, smtputf8 bool) ([]byte, error) {
header("From", fmt.Sprintf("<%s>", m.From.XString(smtputf8))) // todo: would be good to have a local ascii-only name for this address.
header("To", fmt.Sprintf("<%s>", m.To.XString(smtputf8))) // todo: we could just leave this out if it has utf-8 and remote does not support utf-8.
header("Subject", m.Subject)
header("Message-Id", fmt.Sprintf("<%s>", mox.MessageIDGen(smtputf8)))
m.MessageID = mox.MessageIDGen(smtputf8)
header("Message-Id", fmt.Sprintf("<%s>", m.MessageID))
if m.References != "" {
header("References", m.References)
}
header("Date", time.Now().Format(message.RFC5322Z))
header("MIME-Version", "1.0")
mp := multipart.NewWriter(msgw)

View file

@ -233,7 +233,7 @@ Accounts:
const qmsg = "From: <test0@mox.example>\r\nTo: <other@remote.example>\r\nSubject: test\r\n\r\nthe message...\r\n"
_, err = fmt.Fprint(mf, qmsg)
xcheckf(err, "writing message")
_, err = queue.Add(ctxbg, mlog.New("gentestdata"), "test0", mailfrom, rcptto, false, false, int64(len(qmsg)), prefix, mf, nil, true)
_, err = queue.Add(ctxbg, mlog.New("gentestdata"), "test0", mailfrom, rcptto, false, false, int64(len(qmsg)), "<test@localhost>", prefix, mf, nil, true)
xcheckf(err, "enqueue message")
// Create three accounts.

View file

@ -2945,6 +2945,13 @@
"int64"
]
},
{
"Name": "MessageID",
"Docs": "Used when composing a DSN, in its References header.",
"Typewords": [
"string"
]
},
{
"Name": "MsgPrefix",
"Docs": "",

View file

@ -105,6 +105,7 @@ func queueDSN(log *mlog.Log, m Msg, remoteMTA dsn.NameIP, secodeOpt, errmsg stri
From: smtp.Path{Localpart: "postmaster", IPDomain: dns.IPDomain{Domain: mox.Conf.Static.HostnameDomain}},
To: m.Sender(),
Subject: subject,
References: m.MessageID,
TextBody: textBody,
ReportingMTA: mox.Conf.Static.HostnameDomain.ASCII,

View file

@ -104,6 +104,7 @@ type Msg struct {
Has8bit bool // Whether message contains bytes with high bit set, determines whether 8BITMIME SMTP extension is needed.
SMTPUTF8 bool // Whether message requires use of SMTPUTF8.
Size int64 // Full size of message, combined MsgPrefix with contents of message file.
MessageID string // Used when composing a DSN, in its References header.
MsgPrefix []byte
// If set, this message is a DSN and this is a version using utf-8, for the case
@ -199,7 +200,7 @@ func Count(ctx context.Context) (int, error) {
// this data is used as the message when delivering the DSN and the remote SMTP
// server supports SMTPUTF8. If the remote SMTP server does not support SMTPUTF8,
// the regular non-utf8 message is delivered.
func Add(ctx context.Context, log *mlog.Log, senderAccount string, mailFrom, rcptTo smtp.Path, has8bit, smtputf8 bool, size int64, msgPrefix []byte, msgFile *os.File, dsnutf8Opt []byte, consumeFile bool) (int64, error) {
func Add(ctx context.Context, log *mlog.Log, senderAccount string, mailFrom, rcptTo smtp.Path, has8bit, smtputf8 bool, size int64, messageID string, msgPrefix []byte, msgFile *os.File, dsnutf8Opt []byte, consumeFile bool) (int64, error) {
// todo: Add should accept multiple rcptTo if they are for the same domain. so we can queue them for delivery in one (or just a few) session(s), transferring the data only once. ../rfc/5321:3759
if Localserve {
@ -220,7 +221,7 @@ func Add(ctx context.Context, log *mlog.Log, senderAccount string, mailFrom, rcp
}()
now := time.Now()
qm := Msg{0, now, senderAccount, mailFrom.Localpart, mailFrom.IPDomain, rcptTo.Localpart, rcptTo.IPDomain, formatIPDomain(rcptTo.IPDomain), 0, nil, now, nil, "", has8bit, smtputf8, size, msgPrefix, dsnutf8Opt, ""}
qm := Msg{0, now, senderAccount, mailFrom.Localpart, mailFrom.IPDomain, rcptTo.Localpart, rcptTo.IPDomain, formatIPDomain(rcptTo.IPDomain), 0, nil, now, nil, "", has8bit, smtputf8, size, messageID, msgPrefix, dsnutf8Opt, ""}
if err := tx.Insert(&qm); err != nil {
return 0, err

View file

@ -85,11 +85,11 @@ func TestQueue(t *testing.T) {
}
path := smtp.Path{Localpart: "mjl", IPDomain: dns.IPDomain{Domain: dns.Domain{ASCII: "mox.example"}}}
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
mf2 := prepareFile(t)
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, mf2, nil, false)
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, mf2, nil, false)
tcheck(t, err, "add message to queue for delivery")
os.Remove(mf2.Name())
@ -293,7 +293,7 @@ func TestQueue(t *testing.T) {
// Add a message to be delivered with submit because of its route.
topath := smtp.Path{Localpart: "mjl", IPDomain: dns.IPDomain{Domain: dns.Domain{ASCII: "submit.example"}}}
_, err = Add(ctxbg, xlog, "mjl", path, topath, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
_, err = Add(ctxbg, xlog, "mjl", path, topath, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
wasNetDialer = testDeliver(fakeSubmitServer)
if !wasNetDialer {
@ -301,7 +301,7 @@ func TestQueue(t *testing.T) {
}
// Add a message to be delivered with submit because of explicitly configured transport, that uses TLS.
msgID, err := Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
msgID, err := Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
transportSubmitTLS := "submittls"
n, err = Kick(ctxbg, msgID, "", "", &transportSubmitTLS)
@ -325,7 +325,7 @@ func TestQueue(t *testing.T) {
}
// Add a message to be delivered with socks.
msgID, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
msgID, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
transportSocks := "socks"
n, err = Kick(ctxbg, msgID, "", "", &transportSocks)
@ -339,7 +339,7 @@ func TestQueue(t *testing.T) {
}
// Add another message that we'll fail to deliver entirely.
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
msgs, err = List(ctxbg)
@ -473,7 +473,7 @@ func TestQueueStart(t *testing.T) {
}
path := smtp.Path{Localpart: "mjl", IPDomain: dns.IPDomain{Domain: dns.Domain{ASCII: "mox.example"}}}
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), nil, prepareFile(t), nil, true)
_, err = Add(ctxbg, xlog, "mjl", path, path, false, false, int64(len(testmsg)), "<test@localhost>", nil, prepareFile(t), nil, true)
tcheck(t, err, "add message to queue for delivery")
checkDialed(true)

View file

@ -46,7 +46,7 @@ func queueDSN(ctx context.Context, c *conn, rcptTo smtp.Path, m dsn.Message) err
// ../rfc/3464:433
const has8bit = false
const smtputf8 = false
if _, err := queue.Add(ctx, c.log, "", smtp.Path{}, rcptTo, has8bit, smtputf8, int64(len(buf)), nil, f, bufUTF8, true); err != nil {
if _, err := queue.Add(ctx, c.log, "", smtp.Path{}, rcptTo, has8bit, smtputf8, int64(len(buf)), m.MessageID, nil, f, bufUTF8, true); err != nil {
return err
}
err = f.Close()

View file

@ -1678,8 +1678,10 @@ func (c *conn) submit(ctx context.Context, recvHdrFor func(string) string, msgWr
// Add Message-Id header if missing.
// ../rfc/5321:4131 ../rfc/6409:751
if header.Get("Message-Id") == "" {
msgPrefix = append(msgPrefix, fmt.Sprintf("Message-Id: <%s>\r\n", mox.MessageIDGen(c.smtputf8))...)
messageID := header.Get("Message-Id")
if messageID == "" {
messageID = mox.MessageIDGen(c.smtputf8)
msgPrefix = append(msgPrefix, fmt.Sprintf("Message-Id: <%s>\r\n", messageID)...)
}
// ../rfc/6409:745
@ -1870,7 +1872,7 @@ func (c *conn) submit(ctx context.Context, recvHdrFor func(string) string, msgWr
}
msgSize := int64(len(xmsgPrefix)) + msgWriter.Size
if _, err := queue.Add(ctx, c.log, c.account.Name, *c.mailFrom, rcptAcc.rcptTo, msgWriter.Has8bit, c.smtputf8, msgSize, xmsgPrefix, dataFile, nil, i == len(c.recipients)-1); err != nil {
if _, err := queue.Add(ctx, c.log, c.account.Name, *c.mailFrom, rcptAcc.rcptTo, msgWriter.Has8bit, c.smtputf8, msgSize, messageID, xmsgPrefix, dataFile, nil, i == len(c.recipients)-1); err != nil {
// Aborting the transaction is not great. But continuing and generating DSNs will
// probably result in errors as well...
metricSubmission.WithLabelValues("queueerror").Inc()
@ -2564,6 +2566,7 @@ func (c *conn) deliver(ctx context.Context, recvHdrFor func(string) string, msgW
From: smtp.Path{Localpart: "postmaster", IPDomain: deliverErrors[0].rcptTo.IPDomain},
To: *c.mailFrom,
Subject: "mail delivery failure",
References: messageID,
// Per-message details.
ReportingMTA: mox.Conf.Static.HostnameDomain.ASCII,