How to fix outgoing Postfix mail errors on Ubuntu 18.04 SASL authentication failed; server smtp.gmail.com?

Question

postfix

How to fix outgoing Postfix mail errors on Ubuntu 18.04 SASL authentication failed; server smtp.gmail.com? I have been trying to cross with gmail for a whole day / I get
SASL authentication failed errors in the log; server smtp.gmail.com ...............
Did everything according to the instructions https://askubuntu.com/questions/1112772/send-syste...

Answer 1

Answered myself
1) Turn on two-step authorization in your account and make the application in the application will have 12 password with spaces, put it without spaces in sasl_passwd
sudo chmod 400 /etc/postfix/sasl_passwd
sudo postmap /etc/postfix/sasl_passwd
Lastly reload postifx:
sudo /etc /init.d/postfix reload
2) enable the debug log in main.cf
#debug_peer_list=smtp.gmail.com
#debug_peer_level=3
then comment it out. We look at the log var/log/mail.log

Answer 2

Perhaps the Google account is connected with two-factor authentication, via SMS for example. Because of this, the connection fails.
Try enabling the less secure apps option

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