According with this README there is an option to send post commit notification via smtp:
multimailhook.mailer - smtp: use Python's smtplib. This is useful when the sendmail command is not available on the system. This mode can be further customized via the following options:
But i can't realize how to use smtp password with this option. Thank in advance.
It wasn't possible until today, but I've just merged a pull-request adding support for authenticated SMTP: https://github.com/git-multimail/git-multimail/blob/master/git-multimail/README#L272