Sending email from Emacs is remarkably easy for Linux users. The following works for >=Emacs 24; it assumes you have a Gmail account.
1) Open Emacs and hit C-x m to bring up the unsent mail buffer 2) Write a test email and hit C-c C-c to send 3) At the prompts, choose SMTP and then enter smtp.googlemail.com for server. 4) Enter username and password 5) Say yes to save password to ~/.authinfo authentication file. 6) And that's it. It really is that easy.
If you follow the above process you will see that the following are added to your .emacs file
1: '(send-mail-function (quote smtpmail-send-it)) 2: '(smtpmail-smtp-server "smtp.googlemail.com") 3: '(smtpmail-smtp-service 25))
If you’ve saved the password you’ll see that the following has been written to the ~/.authinfo file.
machine smtp.googlemail.com login username port 25 password mypassword
If you’re worried about having that information stored as plaintext, Emacs will read from a ~/.authoinfo.gpg file, if you have GPG installed.
Recently, Gmail has updated its security policies to only accept logins from secure apps. You may have to disable this setting in order to access the account. Given this, and also how much is attached to a Gmail account nowadays, you may want to set up a spare Gmail account just for the purposes of sending email.