Sympthom:

my postfix/dovecot server stops connection requests on port 25 if the mail reject limit exceeds around 400 per minute.

Port 25 is available but no 220 promt is coming. So I assume not enough smtp or amavis deamons on port 10024 10025 are available.

A short postfix reload “solves” the problem, spammer are gone and connections are free agai for real users.

I did review my master.conf an see:

smtp inet n - n - 20 smtpd

-o smtpd_proxy_filter=localhost:10024

-o content_filter=

But no smtp_client_connection_count_limit is set (a la):

smtp inet n - n - 20 smtpd

-o smtpd_proxy_filter=localhost:10024

-o content_filter=

-o smtp_client_connection_count_limit=10

Question:

I’ve domains where the postfix accepts the smtp directly and I’ve domains which have a mailfirewall in front and refuses smtp from all other servers (mailfirewall = mx).

This mailfirewall does also spam and virus checks and sends the “good” mails than to my postfix server.

I assume that the “smtp_client_connection_count_limit” from above affects my mailfirewall too.

How can I exclude my mailfirewall from this client_connection_count_limit (or how can I set a seperate limit for my mailfirewall) – or makes this no sense and the limit set is best solution?

For this mailfirewall I’ve condfigured in main.cf:

check_recipient_access hash:/etc/postfix/recipient_access

:/etc/postfix/recipient_access:

mydomain.tld check_if_mailfirewall_is_sender

main.cf:

check_if_mailfirewall_is_sender =

check_client_access hash:/etc/postfix/mailfirewall-ip,

check_recipient_access pcre:/etc/postfix/nice_mailfirewall_reject.pcre,

reject

Liebe Gruesse,

Georg