Re: [exim] automatically blacklisting clients that fail SMTP…

> From: W B Hacker

> > The checks in rcpt - for spamming from trojaned windozes in LAN and
> > using passwords stolen with trojans.

> IF 'in LAN' really does mean 'Local...' and taking as a given that
> protecting WinDoze from infection is not possible and never will be,
>
> - could you instead operate internally on ONLY a non-standard submission
> port and protocol such that 'house configured' MTA would work, but bots
> assuming 25, 465, 587 and their respective protocols would not even FIND
> the 'real' submission port?

Bots needn't to assume. In order to send via a relay, a bot needs
to know the relay's hostname. How the bot can know the hostname?
By looking into Outlook Express (or Outlook, or Microsoft Internet Mail)
settings. There is the port number there too.
Along with login and password if they are required.
So I don't see a difference at which port Exim accepts submissions.
I have set up my Exim to listen on two ports (25 and another)
only because my old ISP blocked port 25.