Spam attack....

[Ronny T. Lampert]

> Have you tried anything like connection rate throttling?
[...]
> I'm sure there are similar features in Exim or Postfix, but I haven't 
> come over to the "dark side" yet so I don't know their secret incantations.
> 

Just a quick chime in - postfixy is this:

# 30 times per 60 seconds
smtpd_client_connection_rate_limit = 30
client_connection_rate_time_unit = 60s

But that may not the only problem solution; give us some time to think.

Cheers,
Ronny