Normal Net::Telnet and below Commands can help you post a mail without any other modules .

smtp protocol command :

http://the-welters.com/professional/smtp.html

Testing I did is ,

put the telnet to my mail server SMTP port

Connected to mail.bksys.co.in
Escape character is '^]'.
220 mail.bksys.co.in ESMTP Postfix (Debian/GNU)
HELO localhost
250 mail.bksys.co.in
MAIL FROM:sabarinathan@bksys.co.in
250 2.1.0 Ok
RCPT To:sabarinathan@bksys.co.in
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
This is test mail by Telnet via SMTP
.
250 2.0.0 Ok: queued as EC1BD1DC002
VRFY sabarinathan@bksys.co.in
252 2.0.0 sabarinathan@bksys.co.in



Best Regards,
S.Sabarinathan, 

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