On CentOS 7 Linux I run Drupal, which requires users to confirm their mail addresses.
I have modified the postfix config files in the following way:
/etc/postfix/generic:
@www.localdomain [email protected]
/etc/postfix/main.cf:
smtp_generic_maps = hash:/etc/postfix/generic
This results in Drupal sending registration mails to new users which contains the headers:
From: [email protected] <--- non-existing address at my domain
Reply-To: [email protected] <--- my private mail address
This works well (better than earlier, when I set From: to my Gmail address and Gmail was thinking my website was spamming others), but I have a problem:
I do not want to accept any mail addressed to anyone @preferans.de anymore (too much SPAM was pouring in), so I have deleted the MX records in the DNS entry of my server and closed the port 25 by iptables.
Now when a new Drupal user enters a fake address, the registration mail bounces back to [email protected] but my postfix installation can not deliver it:
/var/log/maillog:
Aug 16 18:20:44 www postfix/master[1006]: daemon started -- version 2.10.1, configuration /etc/postfix
Aug 16 22:29:20 pref postfix/cleanup[9031]: 785952C03A8: message-id=<[email protected]>
Aug 16 22:29:20 pref postfix/bounce[9033]: 5B56F2C03A7: sender non-delivery notification: 785952C03A8
Aug 16 22:29:20 pref postfix/qmgr[24449]: 785952C03A8: from=<>, size=3262, nrcpt=1 (queue active)
Aug 16 22:29:20 pref postfix/qmgr[24449]: 5B56F2C03A7: removed
Aug 16 22:29:22 pref postfix/smtp[9009]: connect to preferans.de[88.99.244.39]:25: Connection refused
Aug 16 22:29:22 pref postfix/smtp[9009]: 785952C03A8: to=<[email protected]>, relay=none, delay=1.5, delays=0/0/1.5/0, dsn=4.4.1, status=deferred (connect to preferans.de[88.99.244.39]:25: Connection refused)
Aug 16 22:38:51 pref postfix/qmgr[24449]: 785952C03A8: from=<>, size=3262, nrcpt=1 (queue active)
Aug 16 22:38:51 pref postfix/smtp[9208]: connect to preferans.de[88.99.244.39]:25: Connection refused
Aug 16 22:38:51 www postfix/smtp[9208]: 785952C03A8: to=<[email protected]>, relay=none, delay=571, delays=571/0.01/0.01/0, dsn=4.4.1, status=deferred (connect to preferans.de[88.99.244.39]:25: Connection refused)
Aug 16 22:48:51 www postfix/qmgr[24449]: 785952C03A8: from=<>, size=3262, nrcpt=1 (queue active)
Aug 16 22:48:51 www postfix/smtp[9393]: connect to preferans.de[88.99.244.39]:25: Connection refused
Aug 16 22:48:51 www postfix/smtp[9393]: 785952C03A8: to=<[email protected]>, relay=none, delay=1171, delays=1171/0.01/0.01/0, dsn=4.4.1, status=deferred (connect to preferans.de[88.99.244.39]:25: Connection refused)
Aug 16 23:08:51 www postfix/qmgr[24449]: CF37F2C039F: from=<[email protected]>, size=1234, nrcpt=1 (queue active)
Aug 16 23:08:51 www postfix/qmgr[24449]: 785952C03A8: from=<>, size=3262, nrcpt=1 (queue active)
Aug 16 23:08:51 www postfix/smtp[9797]: connect to preferans.de[88.99.244.39]:25: Connection refused
Aug 16 23:08:51 www postfix/smtp[9797]: 785952C03A8: to=<[email protected]>, relay=none, delay=2371, delays=2371/0.01/0.01/0, dsn=4.4.1, status=deferred (connect to preferans.de[88.99.244.39]:25: Connection refused)
Aug 16 23:08:51 www postfix/smtp[9796]: connect to gamai.com[67.227.226.241]:25: Connection refused
Aug 16 23:08:51 www postfix/smtp[9796]: CF37F2C039F: to=<[email protected]>, relay=none, delay=4588, delays=4588/0.01/0.13/0, dsn=4.4.1, status=deferred (connect to gamai.com[67.227.226.241]:25: Connection refused)
Aug 16 23:48:52 www postfix/qmgr[24449]: 785952C03A8: from=<>, size=3262, nrcpt=1 (queue active)
Aug 16 23:48:52 www postfix/smtp[10420]: connect to preferans.de[88.99.244.39]:25: Connection refused
Aug 16 23:48:52 www postfix/smtp[10420]: 785952C03A8: to=<[email protected]>, relay=none, delay=4772, delays=4772/0.01/0.01/0, dsn=4.4.1, status=deferred (connect to preferans.de[88.99.244.39]:25: Connection refused)
And the queue fills up:
# sudo mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
CF37F2C039F 1234 Wed Aug 16 21:52:22 [email protected]
(connect to gamai.com[67.227.226.241]:25: Connection refused)
[email protected]
785952C03A8 3262 Wed Aug 16 22:29:20 MAILER-DAEMON
(connect to preferans.de[88.99.244.39]:25: Connection refused)
[email protected]
BD4222C03B6 1219 Thu Aug 17 07:48:48 [email protected]
(host mx.yandex.ru[87.250.250.89] said: 451 4.5.1 The recipient <[email protected]> has exceeded their message rate limit. Try again later. 1502957639-8f63s3727h-Dw8G1QLj (in reply to end of DATA command))
[email protected]
-- 6 Kbytes in 3 Requests.
My question is please:
How to configure my postfix installation, so that it drops not delivered mails immediately (but still comes through grey-listing)?
Finally here is the current postconf -n output:
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
html_directory = no
inet_interfaces = localhost
inet_protocols = all
mail_owner = postfix
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
sample_directory = /usr/share/doc/postfix-2.10.1/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_generic_maps = hash:/etc/postfix/generic
unknown_local_recipient_reject_code = 550
Solution for me has been to set
in /etc/postfix/main.cf to decrease the lifetime of bounced messages to 2 days