Running multiple Postfix setups

Today a customer wanted to use their current mail server for sending regular emails to a list with about 200.000 addresses in it. Sure no problem, but this will fill your queue and all other mail from/to your company will get delayed. To avoid this, you can setup Postfix so that it can run a 2nd instance of it’s binaries that has it’s own queue!

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Rate limit incoming mail on Postfix

Today I ran into a problem with one of our ISPConfig 3 installations.

It hosts a domain which seems to be very attractive for spammers, so what happened .. my mail server got hammered by a spam bot net (
not yet blocked by spamhaus as of typing this post).

In ISPConfig 3 Postfix talks with your MySQL server, to check for filters/rules/etc for each mail it receives, this resulted in more problems:
– MySQL reaching it’s max connections of (in my case) 250
– The ISPConfig web interface logging me in/out automatically (because it couldn’t connect to MySQL)
– The hosted websites giving errors because of the same reason.

You can’t completely block these, since the amount of IP different addresses is insane, so let postfix keep track of it and handle the situation!
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