Basic Git configuration (in case you haven’t already done that):
$ git config --global user.email you@example.org
$ git config --global user.name "Your Name"
Git email configuration:
$ git config --global sendemail.smtpserver your_mail_server
$ git config --global sendemail.smtpuser you@example.org
$ git config --global sendemail.smtpserverport your_smtp_port
$ git config --global sendemail.smtpencryption your_encryption_type
Examples
Apply a patch (or simply make a commit) and send it to a mailing list:
$ git am < some_patch
$ git send-email --to=list@example.org HEAD^
Fix last commit and send it:
$ git commit -a --amend
$ git send-email --annotate -v2 HEAD^
Send 3 last commits (see Revision Selection for more info on the notation):
$ git send-email HEAD~3
Send the last commit to list@example.org and make the subject look like
“[reponame][PATCH] commitmsg”. This is useful for sending patches to mailing
lists or programmers with multiple projects:
$ git send-email --subject-prefix="${PWD##*/}][PATCH" \
--to=list@example.org -1
git-send-email(1) manual page. Simple as that. None of that fork & pull request crap.