Hello.
We have some trouble delivering mail to a particular destination. After
something like five deliveries in a few seconds, our IP packets are
dropped for one hour.
I have tried to add a rate delay, but it does not help. This provider
has a lot of different domains and Postfix will start delivery to
several of these domains at the same time. Immediately, we hit the
threshold and get locked out.
Did we miss some setting that can help in this scenario? Getting the
SMTP client to sleep for some seconds after each delivery would probably
do the trick.
Current configuration snippets below.
Thanks,
Anders.
/etc/postfix/transport
123mail.dk cybercity:
12mail.dk cybercity:
12move.dk cybercity:
2night.dk cybercity:
# ... 80 more domains
/etc/postfix/master.cf
cybercity unix - - n - 1 smtp
/etc/postfix/main.cf
cybercity_destination_concurrency_limit=2
cybercity_destination_rate_delay=30s
cybercity_destination_concurrency_failed_cohort_limit=10
