Well, AFAIK pine is simply a mail client, not a mail server. I would reccommend finding out what mail server you run and looking up to see if it will take input directly from the command line (much as sendmail does).

If it does not you could probably find the base code for a POP3 or SMTP client on CPAN which you could install on your web server, making it just another client as far as the server is concerned