Re: [exim] Duplicate emails

schmerold2()gmail.com wrote:

>>>We are getting duplicate emails. It seems to be the same senders,
>>>however not every one of their emails duplicate. 5% of mails from
>>>Charter.net will duplicate, 10% of mails from Cox will duplicate, 100%
>>>of mails from Interfax.net will duplicate.
>>
>>>spamd_address = 127.0.0.1 783

If you get either 1 or 2 instances of each message (not more than 2)
then the cause definitely is a DNS timeout (probably checking RBL/DNSBL).
The result (DNS failure) is cached, so the second time the message is
accepted much faster, so the sender doesn't repeat anymore.

>It does seem like we are going to need to beef up the Exim hardware and
>perhaps go to local RBL.

I'm talking of timeouts while querying external servers, if my guess is
right then upgrade of your hardware will not help.

>>I guess that your spam-filter queries some RBL, and one or more of them
>>timeout because dead or for paying customers only.
>>Try switch spam-filtering via spamd off temporarily.
>>If that doesn't help then try to switch virus-filtering off temporarily.