Interesting, the documentation and the build-in help of dovecot-lda do not mention -r exists :)

case 'r':
	/* final recipient address */
	if (smtp_address_parse_path(ctx.pool, optarg,
	SMTP_ADDRESS_PARSE_FLAG_ALLOW_LOCALPART \|
	SMTP_ADDRESS_PARSE_FLAG_BRACKETS_OPTIONAL,
	&final_rcpt_to, &errstr) < 0) {
	i_fatal_status(EX_USAGE,
	"Invalid -a parameter: %s", errstr);

Btw: Should the error message not read "Invalid -r parameter: %s" instead?

I think the problem is the different handling in Postfix and Dovecot:
Postfix seems to automatically strip the quotes out of the username, at least for SQL lookup (but does the splitting correctly, which Dovecot 2.3 does NOT).
Dovecot does not strip quotes.

What is the recommended (i.e. endorsed by its developers) way for Dovecot to deal with Mail addresses containing Quotation marks? Strip them out? Keep them? Since they are disabled by default (auth_username_chars), it seems like stripping, but then the splitting of local part and domain does not work correctly.
Am I really the first one to play around with this? Does it make sense to prepare patches for example for fixing the splitting?

On a side note: Has support for UTF8 in local parts already landed in Dovecot? I could not find up-to-date information on this topic.

Kind regards,
Philipp

Am 07-Mar-18 um 15:50 schrieb Stephan Bosch:

Op 7-3-2018 om 15:40 schreef Stephan Bosch:

Op 7-3-2018 om 13:46 schreef Philipp Berger:

I wrapped the LDA command in a script. I can see that Postfix passes
"@@mydomain.tld" as the -d argument, without quotes.
I then adapted the script to specifically replace this address with
"@"@mydomain.tld, but this results in the following error message by
Dovecot:

     auth: Info: userdb(?): Username character disallowed by
auth_username_chars: 0x22 (username: "@"@mydomain.tld)

So what would be the appropriate quoting/setting for this address?

Adding " to auth_username_chars would help.

But why are you trying to accept such incredibly horrible email-addresses/usernames?

Also, -d is used to provide the username. For -d, you could leave out the double quotes and provide the full e-mail address--including the required quotes--to the -r argument.

It all depends on what your userdb expects.

Regards,

Stephan.

Am 06-Mar-18 um 15:08 schrieb Stephan Bosch:

Op 6-3-2018 om 14:34 schreef Philipp Berger:

I upgraded to Dovecot 2.3.0.1 as advised, but it still seems broken. In
the Postfix log I now see:

Mar 6 13:49:03 myhost amavis[7165]: (07165-10) K00VtLRHdrYw FWD from
<admin@mydomain.tld> -> <"@"@mydomain.tld>, BODY=7BIT 250 2.0.0 from
MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as B8CA22DA1B37
Mar 6 13:49:03 myhost amavis[7165]: (07165-10) Passed CLEAN
{RelayedInbound}, [someIp]:11439 [someIp] <admin@mydomain.tld> ->
<"@"@mydomain.tld>, Queue-ID: D27792DA167C, Message-ID:
<22b95756-e95e-86cf-219c-3b603f7587c8@mydomain.tld>, mail_id:
K00VtLRHdrYw, Hits: -3, size: 7472, queued_as: B8CA22DA1B37, 1863 ms
Mar 6 13:49:03 myhost postfix/smtp[2329]: D27792DA167C:
to=<@@mydomain.tld>, relay=127.0.0.1[127.0.0.1]:10024, delay=2,
delays=0.15/0.01/0/1.9, dsn=2.0.0, status=sent (250 2.0.0 from
MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as B8CA22DA1B37)
Mar 6 13:49:03 myhost postfix/pipe[2282]: B8CA22DA1B37:
to=<@@mydomain.tld>, relay=dovecot, delay=0.2, delays=0.11/0/0/0.09,
dsn=5.1.1, status=bounced (user unknown)
Mar 6 13:49:03 myhost postfix/cleanup[2280]: EA37E2DA1F80:
message-id=<20180306124903.EA37E2DA1F80@mydomain.tld>
Mar 6 13:49:04 myhost postfix/bounce[2334]: B8CA22DA1B37: sender
non-delivery notification: EA37E2DA1F80
Mar 6 13:49:04 myhost postfix/qmgr[21911]: EA37E2DA1F80: from=<>,
size=9830, nrcpt=1 (queue active)
Mar 6 13:49:04 myhost postfix/qmgr[21911]: B8CA22DA1B37: removed
Mar 6 13:49:04 myhost postfix/pipe[2282]: EA37E2DA1F80:
to=<admin@mydomain.tld>, relay=dovecot, delay=0.07,
delays=0.05/0/0/0.02, dsn=5.3.0, status=bounced (command line usage
error. Command output: lda: Fatal: Invalid -f parameter: Missing
domain )

I can see in my MySQL Log that Dovecot queried at the same time with %n
= "" (empty) and %d = "@mydomain.tld". So now the "@" is dropped
entirely.

What does the "Fatal: Invalid -f parameter: Missing domain" tell us? Do
I need to change the way Postfix calls Dovecot? Add more quotes? :D

Can you check what Postfix is feeding to Dovecot exactly (i.e.,
whether it is properly escaped)? Maybe wrap dovecot-lda in some shell
script and see what is passed.

Regards,

Stephan.

Kind regards,
Philipp

Am 04-Mar-18 um 21:12 schrieb Stephan Bosch:

Op 3/1/2018 om 2:07 PM schreef Philipp Berger:

Dear all,

I have a working setup with Postfix + Dovecot, storing users in a
MySQL
table.

I ran into problems setting up and using a mail address like
a"@"b@mydomain.tld, which by RFC should be valid, but leads to
problems
in Dovecot. From my debugging, I can see that on the lookup, Dovecot
replaces %n with "a" (quotes added by me) and %d with "b@mydomain.tld"
(quotes added by me). So the original quotes are gone, and the
domain/user split is incorrect.

I am not sure of Postfix passes the address without quotes to
Dovecot or
whether Dovecot can not handle quotes correctly, but I was hoping that
someone with more insight into Dovecot could help me out here.

System Info: Debian 9, Postifx 3.1.6-0+deb9u1, Dovecot 2.2.27-3+deb9u1
Postfix master.cf for Dovecot:
dovecot unix -       n       n       -       - pipe
    flags=DRhu user=virtual:virtual
argv=/usr/lib/dovecot/dovecot-lda -f
${sender} -d ${user}@${nexthop}

I am grateful for any hints :)

Thank you in advance, kind regards,

Yeah, Dovecot v2.2 is doing some funky stuff with SMTP address parsing.
Dovecot v2.3 should do a better job. I am still not sure if this can be
fixed well for Dovecot v2.2.

Regards,

Stephan.