Hiya, I'm having sort of a strange problem with my postfix installation.
I have Local users and users with forwards. Some can have more than one forward, say we have Original-Recipient a...@a.test<mailto:a...@a.test> that forwards to local b...@a.test<mailto:b...@a.test> and remote c...@b.test<mailto:c...@b.test> . At first, my remote user did not get the mail at all. I suspected the remote end, but some debugging showed that it was the Postfix that simply did not deliver to remote destinations when forwarding. Having thought about this for some time I ended up with a solution that at least managed to ship mails to the remote user. But now the local user gets 2 mails, one that is clearly destined for b...@a.test<mailto:b...@a.test>, but also one that is destined for c...@b.test<mailto:c...@b.test>. Postfix receives the mail, handles greylisting, quota, spf, dkim and other lovelies. Then sends it off via "content_filter=scan:127.0.0.1:10025" to clamsmtp. This returns on port 10026 with this listener from master.cf 127.0.0.1:10026 inet n - - - - smtpd -o spamassassin_destination_recipient_limit=1 -o content_filter=spamassassin -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks -o smtpd_helo_restrictions= -o smtpd_client_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o mynetworks_style=host -o default_transport=smtp: -o smtpd_authorized_xforward_hosts=127.0.0.0/8 Here it then sends it further into the content_filter=spamassassin spamassassin unix - n n - - pipe flags=DROXhu user=vmail:vmail argv=/usr/local/bin/xMTPDeliver ${sender} ${user} ${nexthop} xMTPDeliver examines ${user} and ${nexthop} to see where it is supposed to go local/remote. If it is local, we use dovecot-lda to deliver it directly into users spam-folder if marked as spam, otherwise into users inbox. Fairly straight forward. #!/bin/bash # Author: s...@danskkabeltv.dk - 20170507 # Description: # Check if USER@DOMAIN is a local delivery. # If it is - deliver through dovecot-LDA after scanning. # Otherwise ship via SMTP (probably localhost..) SMTP="/usr/sbin/sendmail -oi" LMTP="/usr/lib/dovecot/deliver" SPAM="/usr/bin/spamc" LOG="/usr/bin/logger -p mail.info -t filter" ## Final Destination delivery. SENDER=$1 USER=$2 DOMAIN=$3 # Note: aliases/forwards should be resolved at this point - # otherwise they will be put in queue again. # If 0 - then IS_LOCAL=`/usr/sbin/postmap -q ${USER}@${DOMAIN} mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf | wc -l` ## This local. Send to spamc + dovecot-LDA if [ ${IS_LOCAL} -gt 0 ] ; then ${LOG} "Delivering to local user (${USER}@${DOMAIN})" ${SPAM} -f -e ${LMTP} -f ${SENDER} -d ${USER}@${DOMAIN} else ## External domain - deliver through SMTP ${LOG} "Delivering to remote user (${USER}@${DOMAIN})" ${SPAM} -f -e ${SMTP} -f ${SENDER} -t ${USER}@${DOMAIN} But somehow, somewhere - b...@a.test<mailto:b...@a.test> gets 2 mails, second mail b...@a.test<mailto:b...@a.test> does not even mention b...@a.test<mailto:b...@a.test> - but through and through looks like a mail to c...@b.test<mailto:c...@b.test> .. The debug shows that 2 mails are being generated as expected, one goes through the IS_LOCAL statement, whereas the other goes through the "Deliver through SMTP" and I suspect it is here something goes awry, that it sees "Oi, this one is really for a...@a.test<mailto:a...@a.test> - which is also aliased to b...@a.test<mailto:b...@a.test>". But I cannot see where to fix that particular problem. Any takers (or suggestions for changes) Best regards Søren P. Skou
