[Mimedefang] suggestion - filter_begin

David F. Skoll dfs at roaringpenguin.com
Thu Jun 9 07:27:18 EDT 2005


dead hero wrote:

>>1) MX records are not required, when non-existant
>>the A record will be used.

> are you sure about that?

He's right.  Check the RFCs.

Also, your code will block mail if there's a temporary
DNS error.  You should distinguish between SERVFAIL
and NXDOMAIN status codes from the DNS lookup.

Also, some domains can publish bogus MX and/or A records,
meaning mail will still sit in the queue until it times
out.  If you search the mailing list archives for
"Bad MX", you should find some more complete solutions.
See for example:

http://lists.roaringpenguin.com/pipermail/mimedefang/2003-September/016802.html

Regards,

David.



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