421 Too many concurrent SMTP connections

[Hostbox.be]

Hi all

On one specific server, my clients are getting often following message when sending emails:

421 Too many concurrent SMTP connections

Also I get almopst every hour a meesage from the server: "exim failed"

I already set smtp_accept_max = 200 (default is 100), but no solution.


When I look for IP's connecting to port 25:

netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

I see a lot of IP's with 1 or 2 connections to my server, so that seems normal, but at the end of the list I see many connections from my 2 DNS servers and from 127.0.0.1

The 127.0.0.1 is normal I think because this is also listed on all my other servers, but not from my 2 DNS servers that are configured in /etc/resolv.conf

These last two are eating up all SMTP connections, does someone know a solution for this ?


Linux CentOS 4
WHM 11.2.0
cPanel 11.11.0-S18033
exim-4.63-1

[bazzi]

Do you have a program that is reporting something from that servers to your by email?

[bazzi]

you can make a ACL file to block the smtp servers.

You can use the http://www.configserver.com/free/eximdeny.html
as guide to add it.