Setup sSMTP:

To configure sSMTP you can use the ssmtp-config command. Run it and answer the questions posed.    Please enter the full qualified hostname (foo.bar.baz) of your box: foo.bar.baz    Please enter the "mail name" of your system. This is the hostname    portion of the address to be shown on outgoing news and mail messages.    The default is foo.bar.baz, your system's host name.        Mail name [foo.bar.baz]: bar.baz        Please enter the full qualified hostname of your mail hub: mail.bar.baz    Please enter the smtp port number [25]:        Please check the configuration file /etc/ssmtp/ssmtp.conf for correctness. The example above assumes that your computer is named foo.bar.baz, your e-mail address is [email protected], and your e-mail server is named mail.bar.baz. This will give a configuration file like the one below. /etc/ssmtp/ssmtp.conf    #    # /etc/ssmtp.conf -- a config file for sSMTP sendmail.    #    # The person who gets all mail for userids < 10    root=postmaster    # The place where the mail goes. The actual machine name is required    # no MX records are consulted. Commonly mailhosts are named mail.domain.com    # The example will fit if you are in domain.com and you mailhub is so named.    mailhub=mail.bar.baz    # Where will the mail seem to come from?    #rewriteDomain=bar.baz    # The full hostname    hostname=foo.bar.baz    # Set this to never rewrite the "From:" line (unless not given) and to    # use that address in the "from line" of the envelope.    #FromLineOverride=YES The To: and From: lines in a mail are merely comments in a text file. When the mail client contacts a mail server to have a mail sent the sender and receiver are presented through the "MAIL FROM:" and "RCPT TO:" smtp commands. (How the sender presented itself is later available in the "From_ header" or "envelope from", but not all mailbox formats save this line.) Normally sSMTP presents you as your local (cygwin) user at hostname. If `rewriteDomain=bar.baz' is uncommented, ssmtp always rewrites the `From' envelope and the `From:' line so that the domain name is set to bar.baz. If the option `FromLineOverride' is set to YES, ssmtp uses the same `From' in the mail envelope as you have written into the `From:' line of your mail. In case you send mail through another server than the one providing your e-mail address, it is not likely that your mails come through unless the envelope from presents you as a valid user at the server. That is, you need the From: and From_ lines to differ. (For example, if the cygwin user cygwinuser wishes to send a mail with the From: line reading [email protected] through the mail server mail.bar.baz, he probably needs the envelope from to be [email protected].) You can do this by editing the revaliases file. /etc/ssmtp/revaliases    # sSMTP aliases    #    # Format: local_account:outgoing_address:mailhub    #    # Example: root:[email protected]:mailhub.your.domain:[port]    # where [port] is an optional port number that defaults to 25.    cygwinuser:[email protected]:mail.bar.baz

Mutt + sSMTP:

To tell Mutt to use your configured sSMTP to send mails for all users you add a line:     set sendmail = "/usr/sbin/ssmtp.exe" to the global Muttrc, but be aware that next time you install Mutt you will get a new Muttrc that overwrites this one. One way to make upgrading simpler (if you have made several adjustments) could be to write an /etc/Muttrc.local, and last in /etc/Muttrc only add a line reading source /etc/Muttrc.local. After an upgrade you will then only have to add this line again (and test that all work as expected still). To use authentication (AUTH LOGIN) with sSMTP you add a line like:     set sendmail = "/usr/sbin/ssmtp.exe -auUSERNAME -apPASSWORD" which you, of course, only want in your personal .muttrc.

Links and Docs:

Mutt Cygwin Binary of sSMTP-2.38.7 for Cygwin (maintained cygwin package) /usr/doc/Cygwin/ssmtp-2.38.7.README (2001-10-09) 'man ssmtp'