Tomas Macek:
> I'd like to use postcreen as some kind of spam protection. According to
> documentation
>
> * postscreen(8) should not be used on SMTP ports that receive mail
> from end-user clients (MUAs). In a typical deployment, postscreen(8) is
> used on the "port 25" service, while MUA clients submit mail via the
> submission service (port 587) which normally requires client
> authentication.
This is the recommended way to separate MTA-to-MTA traffic from
MUA-to-MTA traffic.
> But we have clients, that send mails on both port 25 and 587.
Convert them to use port 587, or whitelist them if they have an
IP address in a known range.
> I really cannot use postscreen? I don't understand why exactly.
> What will happen if I use it?
You will be using the software in an unsupported manner. Therefore,
no-one including myself will be able to help you "fix" the "problem".
Wietse
