Why can't postfix emails be sent?

Question

linux

Hello! postfix is ​​delaying the sending of a mail, this is what it says:
Dec 27... to ,
relay=smtp.gmail.com[64.233.161.109]:587, delay=386/0.05/0 dsn=4.7.8, status=deferred (SASL authentication server smtp.gmail.com[64.233.161.109] said: 535-5.7.8 Username and Password not accepted

. even changed the password and restarted apache, who came across, tell me

Answer 1

Well, Google, obviously, believes that they are wrong. the log says "SASL authentication failed" in black and white.
And more importantly, "Username and Password not accepted. Learn more .."
you cut off the phrase, and there is a link, so follow this link and carefully read what Google writes about how exactly mail forwarding through their SMTP server should work.