[Mimedefang] relay_is_blacklisted_multi() multithreading problems?

[Erik Hensema / HostingXS]

Dear list,

Recently I have developed my own custom mimedefang-filter. All seems to be 
working fine, except that some mails are misclassified as spam.

relay_is_blacklisted_multi() seems to be the culprit. Are there any 
multitheading issues with this function?

My filter first calls relay_is_blacklisted_multi() with a list of dns 
whitelists. When $RelayAddr is whitelisted, the filter skips the second step, 
in which dns blacklists are checked.

However, in some (rare) cases relays are blocked even though there are 
whitelisted and not blacklisted on any blacklist.
I can't see how this can be caused by my filter code.

The server I'm running mimedefang on is fairly busy. Typically 3-4 mimedefang 
childs are running. We're peaking at about 2 smtp connections per second 
sustained for several minutes. Typical load is 1 smtp connection per second.

Because of the apparent random results, I suspect this to be a thread-safety 
problem.

I'm running on:
opensuse 10.3
perl 5.8.8
glibc 2.6.1
mimedefang 2.67

-- 
Met vriendelijke groet,


Erik Hensema / HostingXS Internet Services