[CentOS] Antispam with Postfix

[Ned Slider]

Bowie Bailey wrote:
> Joseph L. Casale wrote:
>>
>> 2. I use backup mx's, my current solution probably could work in this scenario but
>> the support mechanism behind it is *very* weak and I can't get a perfect setup
>> working. Spam hits the primary for a domain, gets blocked and then tries my secondary
>> which sometimes accepts it, after which the primary always accepts from the secondary.
>>   
> 
> If you have a secondary mx, it MUST have the same (if not more
> aggressive) spam prevention as your primary for this exact reason.  You
> also need to make sure that the secondary can reject mail for
> non-existent users so you don't send backscatter when the primary
> rejects the mail.
> 

Personally I'd just drop the secondary mx completely and let the sending 
smtp server queue the mail whenever you're offline. Makes life a lot 
simpler.