Gmail POP3 benötigt heutzutage ein App-Passwort

[JammyDodger]

Your one sounds more like the recent change that now makes you use 2FA and App Password for your google account:

Connection to the POP3 server is failing with an authentication error. Please check your POP3 settings

I recommend turning on 2FA on the account and setting up an App Password for Discourse. The policy change is about the “allow less secure app access” option being deprecated. More info on this here: