Multiple Postfix smtp instances

[Dhawal Doshy]

Dhawal Doshy wrote:
> Jan Brinkmann wrote:
>> Hi,
>>
>> is it possible to have multiple smtpd instances of postfix running on
>> different IPs where one instance is simple running to do SASL based
>> mail relaying (without mailscanner) and the other one can act as the
>> MX for virtual domains? On servers where I use amavis, it's possible
>> to specify multiple smtpd lines where one has the content_filter set
>> to an empty string. I thought it would also be possible to do this
>> with header_checks, but it doesnt work as expected:
>>
>> 1.2.3.4:smtp      inet  n       -       n       -       -    smtpd
>>   -o header_checks=
>> 1.2.3.5:smtp      inet  n       -       n       -    -    smtpd
>>     
>> The second instance (the one listening on 1.2.3.5) would be the one
>> where the mails are set to a HOLD state to enable mailscanner. The
>> other one would be the one which is used to relay mails for sasl
>> authenticated users. If I try to do it this way, all mails get
>> filtered by mailscanner. If I go the other way, with header_checks
>> in main.cf set to an empty string and header_checks defined in the
>> master.cf no mails get scanned at all:
>>
>> 1.2.3.4:smtp      inet  n       -       n       -       -    smtpd
>>   -o header_checks=regexp:/etc/postfix/mailscanner_hold
>> 1.2.3.5:smtp      inet  n       -       n       -       -    smtpd
>>  
>>
>> Any ideas if this can be done, and which way would be correct?
> 
> See..
> http://www.postfix.org/BUILTIN_FILTER_README.html#remote_only
> http://www.seaglass.com/postfix/turning_off_body_checks.html
> 
> You approach is right, just use the 
> receive_override_options=no_header_body_checks option..

BTW, i would recommend virus checking and rate controls on the 
outbound.. spam checks though can be entirely optional.

- dhawal