You could use Socket;, connect to the remote MTA and speak SMTP yourself. It's not that hard for simple purposes. Here's a sample telnet session transcript:

$ telnet localhost 25
! Trying 127.0.0.1...
! Connected to localhost.
! Escape character is '^]'.
< 220 qwurx ESMTP
> HELO localhost
< 250 qwurx
> MAIL FROM: <shmem@qwurx>
< 250 ok
> RCPT TO: <shmem@qwurx>
< 250 ok
> DATA
< 354 go ahead
> From: shmem <shmem@qwurx>
> To: myself <shmem@qwurx>
> Content-Type: text/plain; charset=iso-8859-1
> Content-Transfer-Encoding: 8bit
> Subject: Benevolent Advice
>
> get a clue, quick ;-)
> .
< 250 ok 1169199915 qp 22510
> QUIT
< 221 qwurx
! Connection closed by foreign host.
[download]

Lines beginning with "! " are diagnostics from telnet. Lines beginning with "> " are sent to the server, those with "< " are read from remote. See also RFC 2821.

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}