(08-25-2023, 07:02 PM)taylortbb Wrote:(08-25-2023, 03:07 PM)Bytor Wrote: It is more than just a GMail only. Hotmail/Outlook Live support it, MS Exchange supports it, my email domain hoster ForwardEmail.net supports it, Postfix has supported it since v2.11 in 2014, and many more.
Sure, but Dan is right it's not a SMTP feature. It's just something Gmail did and was then widely copied. But it's a mail server feature, as far as the SMTP protocol is concerned the + has no special meaning, and is just a regular character in the email address.
RFC 3598, 2003
https://datatracker.ietf.org/doc/html/rfc3598
GMail wasn't launched until 2004. April 1st, for those who remember.
Using thE + like that in SMTP addressing has been around a long time, and not just some GMail enhancement.