Function used to send the current buffer as mail. The default is message-send-mail-with-sendmail. If you prefer using MH instead, set this variable to message-send-mail-with-mh.

Most versions of MH doesn't like being fed messages that contain the headers in this variable. If this variable is non-nil (which is the default), these headers will be removed before mailing when sending messages via MH. Set it to nil if your MH can handle these headers.