I'm trying to set up a very low traffic postfix mail server using:
- A Simple content filter (http://www.postfix.org/FILTER_README.html#simple_filter). It's way simpler than the advanced one and the traffic is low.
- dovecot as a delivery agent. (Because of maildir quotas and sieve filters)
always_bccto keep copies of every mail sent. (Bussiness rules)
My relevant configs are:
master.cf
smtp inet n - y - - smtpd
-o content_filter=filter:dummy
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
qmgr unix n - n 300 1 qmgr
tlsmgr unix - - y 1000? 1 tlsmgr
rewrite unix - - y - - trivial-rewrite
bounce unix - - y - 0 bounce
defer unix - - y - 0 bounce
trace unix - - y - 0 bounce
verify unix - - y - 1 verify
flush unix n - y 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - y - - smtp
relay unix - - y - - smtp
-o syslog_name=postfix/$service_name
showq unix n - y - - showq
error unix - - y - - error
retry unix - - y - - error
discard unix - - y - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - y - - lmtp
anvil unix - - y - 1 anvil
scache unix - - y - 1 scache
postlog unix-dgram n - n - 1 postlogd
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
filter unix - n n - 10 pipe
flags=Rq user=filter null_sender=
argv=/var/spool/filter/scripts/filter.sh -f ${sender} -- ${recipient}
dovecot unix - n n - - pipe
flags=DRhu user=vmail:mail argv=/usr/lib/dovecot/dovecot-lda -f ${sender} -d ${recipient}
main.cf (relevant parts only)
always_bcc = seccopies@mydomain.example
virtual_transport = dovecot
dovecot_destination_recipient_limit = 1
/var/spool/filter/scripts/filter.sh
#!/bin/sh
/usr/bin/cat | /var/spool/filter/scripts/mailfilter | /usr/sbin/sendmail -G -i "$@"
exit $?
- All my users have emails in "(Initial).surname@mydomain.example" format
- There are security groups that act as roles and each one has emails in "role@mydomain.example" format.
- Basically, a role email function as an alias to several users.
So, I can reuse the same Roles/Groups I use to set permissions, and not using the users directly.
For example
- my user email is y.hernandez@mydomain.example
- I'm a member of role I.T.Department (informatics@mydomain.example)
- I'm a member of some other roles, but my main role is "I.T.Department"
- Because I'm a member of this group/role I have certain privileges, as the other members and every mail sent to informatics@mydomain.example will reach me and the other members.
So far, so good... But my boss wants that every mail I send uses the informatics@mydomain.example (role) address instead of y.hernandez@mydomain.example (user). i.e., that every mail sent uses the principal role email, not the user email.
/var/spool/filter/scripts/mailfilter is an in-house made filter that just does that (changes "from" addresses from "(Initial).surname@" to "role@" checking an LDAP server).
It never fails (In case of any error condition, it just copies standard input into standard output and no modification is made, so no address change, but the mail is not lost).
The problem is, when I send an email, it delivers two copies to seccopies@mydomain.example as seen in the logs, not one copy as expected.
Dec 16 16:23:08 correo2 postfix/smtpd[32453]: connect from informatica1.mydomain.example[10.128.159.15]
Dec 16 16:23:08 correo2 postfix/smtpd[32453]: DD925380C87: client=informatica1.mydomain.example[10.128.159.15], sasl_method=LOGIN, sasl_username=y.hernandez@mydomain.example
Dec 16 16:23:08 correo2 postfix/cleanup[32456]: DD925380C87: message-id=<002401d91194$982edba0$c88c92e0$@mydomain.example>
Dec 16 16:23:09 correo2 postfix/qmgr[32275]: DD925380C87: from=<y.hernandez@mydomain.example>, size=2749, nrcpt=2 (queue active)
Dec 16 16:23:09 correo2 postfix/pickup[32274]: AAFEF380C8D: uid=110 from=<y.hernandez@mydomain.example>
Dec 16 16:23:09 correo2 postfix/pipe[32457]: DD925380C87: to=<seccopies@mydomain.example>, relay=filter, delay=0.81, delays=0.11/0/0/0.7, dsn=2.0.0, status=sent (delivered via filter service)
Dec 16 16:23:09 correo2 postfix/pipe[32457]: DD925380C87: to=<y.hernandez@mydomain.example>, orig_to=<informatics@mydomain.example>, relay=filter, delay=0.81, delays=0.11/0/0/0.7, dsn=2.0.0, status=sent (delivered via filter service)
Dec 16 16:23:09 correo2 postfix/qmgr[32275]: DD925380C87: removed
Dec 16 16:23:09 correo2 postfix/cleanup[32456]: AAFEF380C8D: message-id=<002401d91194$982edba0$c88c92e0$@mydomain.example>
Dec 16 16:23:09 correo2 postfix/qmgr[32275]: AAFEF380C8D: from=<y.hernandez@mydomain.example>, size=2927, nrcpt=3 (queue active)
Dec 16 16:23:10 correo2 dovecot: lda(seccopies@mydomain.example)<32488><2DSfML3hnGPofgAA0V72BQ>: msgid=<002401d91194$982edba0$c88c92e0$@mydomain.example>: saved mail to INBOX
Dec 16 16:23:10 correo2 postfix/pipe[32473]: AAFEF380C8D: to=<seccopies@mydomain.example>, relay=dovecot, delay=1.1, delays=0.79/0/0/0.28, dsn=2.0.0, status=sent (delivered via dovecot service)
Dec 16 16:23:10 correo2 dovecot: lda(seccopies@mydomain.example)<32490><Au2fML3hnGPqfgAA0V72BQ>: msgid=<002401d91194$982edba0$c88c92e0$@mydomain.example>: saved mail to INBOX
Dec 16 16:23:10 correo2 postfix/pipe[32471]: AAFEF380C8D: to=<seccopies@mydomain.example>, relay=dovecot, delay=1.1, delays=0.79/0/0/0.34, dsn=2.0.0, status=sent (delivered via dovecot service)
Dec 16 16:23:10 correo2 dovecot: lda(y.hernandez@mydomain.example)<32489><BE2gML3hnGPpfgAA0V72BQ>: msgid=<002401d91194$982edba0$c88c92e0$@mydomain.example>: saved mail to INBOX
Dec 16 16:23:10 correo2 postfix/pipe[32470]: AAFEF380C8D: to=<y.hernandez@mydomain.example>, relay=dovecot, delay=1.1, delays=0.79/0/0/0.35, dsn=2.0.0, status=sent (delivered via dovecot service)
Dec 16 16:23:10 correo2 postfix/qmgr[32275]: AAFEF380C8D: removed
Dec 16 16:23:11 correo2 postfix/smtpd[32453]: disconnect from informatica1.mydomain.example[10.128.159.15] ehlo=1 auth=1 mail=1 rcpt=1 data=1 quit=1 commands=6
uid=110 is "filter" user uid. "From" is only changed in the headers, inside of the email, so it doesn't show on the logs.
Everything is running as it should be except this double delivery detail. I haven't tried, but I am sure that if I remove dovecot from the equation, it all works. But I lose the sieve rules and maildir quotas. So...
Any idea of how I can fix it?
