That is easy.
Have your users connect to the submission port, and let everyone
else connnect to the smtp port. Then, specify "=o content_filter=whatever"
for the smtp port and not for the submission port.
Yes Wietse, I've considered this simple and clean option, but we're a
hosting company and the costumers are to lazy to understand and accept
an approach like this.
If you are taking in all mail on port 25 then you are making mail
handling more complicated than it needs to be.
I agree... but ¿is there no more alternatives?
Maybe if I want all mail on port 25, I have to hack the Perl filter code
and working on this level, not in Postfix level.
--
I must not fear. Fear is the mind-killer. Fear is the little-death that
brings total obliteration. I will face my fear. I will permit it to pass
over me and through me. And when it has gone past I will turn the inner
eye to see its path. Where the fear has gone there will be nothing. Only
I will remain.
Bene Gesserit Litany Against Fear.