Dynamic tags in email address

[Felix Gustavsson]

I'm trying to get dynamic tagging (user+sometag at example.com) to work on 
a mail server I'm setting up, however it only works as long as it's sent 
to the main user and not to aliases.

virtual-alias-maps query: SELECT get_email_alias_dyn('%s')
virtual-mailbox-domains query: SELECT 1 FROM domain WHERE name='%s'
virtual-mailbox-maps query: SELECT 1 FROM user_alias INNER JOIN domain 
ON user_alias.domainID = domain.id WHERE user_alias.primary = 1 AND 
CONCAT(user_alias.name, '@', domain.name)='%s'

"get_email_alias_dyn()" is a stored function which returns the 
destination email, so alias+tag at example.com returns user at example.com, 
alias at example.com returns user at example.com and so on.

It works perfectly fine when the mail does not contain any tags 
(alias at example.com or user at example.com) or if it's the primary email 
which contains tags (user+sometag at example.com), but when it's tags on an 
alias the mail is bounced due to "user unknown".

I tried modifying the dovecot service in master.cf so the addresses can 
be filtered with Sieve (http://wiki2.dovecot.org/LDA/Postfix), but that 
did not solve the issue either, so I have not idea where it goes wrong 
or how to solve it.

I have included the logs from when I sent to alias+tag at example.com below:

Oct 25 19:54:20 xx postfix/smtpd[10987]: connect from 
mail-wg0-f50.google.com[74.125.82.50]
Oct 25 19:54:21 xx postfix/smtpd[10987]: 10585DFA63: 
client=mail-wg0-f50.google.com[74.125.82.50]
Oct 25 19:54:21 xx postfix/cleanup[10995]: 10585DFA63: 
message-id=<CAGPeO-YcJwbRJb-Gfga+G_vKqj9cm80rMZf9LAfENRCFfxLVAg at mail.gmail.com>
Oct 25 19:54:25 xx postfix/qmgr[9945]: 10585DFA63: from=<xx at gmail.com>, 
size=1743, nrcpt=1 (queue active)
Oct 25 19:54:25 xx postfix/smtpd[10987]: disconnect from 
mail-wg0-f50.google.com[74.125.82.50]
Oct 25 19:54:25 xx dovecot: auth-worker(11000): mysql(127.0.0.1): 
Connected to database mailcp
Oct 25 19:54:25 xx postfix/pipe[10998]: 10585DFA63: to=<xx+test at xx.com>, 
relay=dovecot, delay=5.4, delays=5.4/0/0/0.03, dsn=5.1.1, status=bounced 
(user unknown)
Oct 25 19:54:25 xx postfix/cleanup[10995]: D39B2DFC7D: 
message-id=<20141025175425.D39B2DFC7D at xx.com>
Oct 25 19:54:25 xx postfix/bounce[11002]: 10585DFA63: sender 
non-delivery notification: D39B2DFC7D
Oct 25 19:54:25 xx postfix/qmgr[9945]: D39B2DFC7D: from=<>, size=3937, 
nrcpt=1 (queue active)
Oct 25 19:54:25 xx postfix/qmgr[9945]: 10585DFA63: removed
Oct 25 19:54:26 xx postfix/smtp[11004]: D39B2DFC7D: to=<xx at gmail.com>, 
relay=gmail-smtp-in.l.google.com[74.125.195.27]:25, delay=0.24, 
delays=0/0/0.16/0.07, dsn=2.0.0, status=sent (250 2.0.0 OK 1414259666 
d8si5463492wiv.41 - gsmtp)
Oct 25 19:54:26 xx postfix/qmgr[9945]: D39B2DFC7D: removed

The dovecot-sql.conf.ext file looks like this:

driver = mysql
connect = host=127.0.0.1 dbname=mailcp user=mailcp password=xxx
default_pass_scheme = SHA512-CRYPT
password_query = SELECT CONCAT(user_alias.name, '@', domain.name) as 
user, user.password as password, concat('*:bytes=', (CASE WHEN 
user.quota  -1 THEN user.quota ELSE domain.quota END)*1000000) AS 
userdb_quota_rule FROM user INNER JOIN user_alias ON user.id = 
user_alias.userID AND user_alias.primary = 1 INNER JOIN domain ON 
user_alias.domainID = domain.id WHERE CONCAT(user_alias.name, '@', 
domain.name) ='%u' AND user.status = 1
user_query = SELECT CONCAT('/var/mail/vmail/', domain.name, '/', 
user_alias.name) as home, 5000 AS uid, 5000 AS gid, concat('*:bytes=', 
(CASE WHEN user.quota != -1 THEN user.quota ELSE domain.quota 
END)*1000000) AS userdb_quota_rule FROM user INNER JOIN user_alias ON 
user.id = user_alias.userID AND user_alias.primary = 1 INNER JOIN domain 
ON user_alias.domainID = domain.id WHERE CONCAT(user_alias.name, '@', 
domain.name) ='%u' AND user.status = 1