[Haifux] State-dependent firewall and Gmail spam filtering

Eli Billauer eli at billauer.co.il
Tue Jan 15 10:20:10 MSK 2013

Hello all,

I asked these two questions in a previous mail which you all ignored. 
Which was probably because I mixed it with announcing that our server 
has moved. So here we go again:

(1) For some reason, the server's firewall doesn't handle --state 
RELATED, ESTABLISHED properly. In fact, this rule doesn't catch any 
input packets at all, even when the server initiates a connection! In 
particular, it doesn't let through answers to its own DNS queries (port 
53) on UDP, which is elementary. The server is an openVZ VPS running 
CentOS 5.6. Ideas?

(2) I've noted that administrative messages from mailman (the mailing 
list manager), e.g. subscription confirmation messages, go to Gmail's 
spam folder. The rDNS for haifux.org is set up properly, and still. From 
what I understand, the mailing list messages themselves go by fine. Any 
comments? Insights? I have reasons to believe this is a widespread 
issue, but how is it solved?


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