in reply to
An SMTP server in Perl
I'm sorry my post did not make it to The Monastery Gates, but you can find it right there. It is about Ultimail.pm, a module I wrote to send emails without your ISP's mailserver.
Ultimail.pm is *not* similar to this SMTP daemon, since you actually use this daemon as a SMTP server, whereas you use Ultimail.pm as a replacement of Mail::Sender (for example), when you do not want to have to specify a mailserver to forward your email (Ultimail.pm talks directly to the target SMTP server).
I must say that there exist already a module called Net::SMTP (click a second time to search on CPAN), which is supposed to work the same way as the daemon presented here (although everytime I tried to use Net::SMTP on Win32 it failed (program hanged - doing nothing) - and I see that somebody got this daemon to work under Win32).