;; Please add these lines in your .emacs(_emacs).
;;
-;;(setq send-mail-function 'smtpmail-send-it)
+;;(setq send-mail-function 'smtpmail-send-it) ; if you use `mail'
+;;(setq message-send-mail-function 'smtpmail-send-it) ; if you are using Gnus.
;;(setq smtp-default-server "YOUR SMTP HOST")
;;(setq smtp-service "smtp")
;;(setq smtp-local-domain "YOUR DOMAIN NAME")