Leaderboard

the php mail function is NOT a mail server. it provides a way for php to interface with the sending mail server at your web hosting, typically though a sendmail binary program on the host system. on your web hosting, there is a mail server that is being used as the sending mail server. since it is unlikely that you are using google cloud web hosting (you probably would have mentioned this) and/or a gmail mail server (this requires smtp authentication, which the php mail() function does not support), the From: mail domain MUST correspond to the domain of your web hosting. you cannot just makeup and put in an @gmail.com email address.