SMTPEditRedirected from Simple Mail Transport ProtocolCreated 7/11/2007, updated 3/12/2020SMTP or Simple Mail Transport Protocol is defined in RFC 821 and extended/refined in RFC 2821. In November 2009 I started using AuthSMTP as an external SMTP host. See also Wikipedia article on SMTP: http://en.wikipedia.org/wiki/SMTP smtpwiki