SMTP does not send emails, they remain in the outbox

I manage two Gmail accounts. One works correctly, the other gives problems to send mails. It started to fail 48 hours ago, before it had been fine for more than 3 years. I have uninstalled EmClient, reinstalled and opening both accounts again. Everything remains the same, one of the accounts still does not send emails. The SMTP settings are identical to the other Gmail account which works fine. I don’t know what else to look at. Does anyone have any idea how to fix it?

Is the one that fails is setup with a username and password, whereas the one that works doesn’t have a username and password? If that is the case, you will need to remove the one with username and password, then add it back again so it is setup with oAuth.

See: Google ‘less secure apps’ access and what it means for eM Client | eM Client

Otherwise, go to Menu > Operations > Log tab, and find the SMTP error for that account tha fails.

There is no way to get SMTP to work. Not even with the Google apps password.

The gentlemen of Google have changed something, because, suddenly, the SMTP has begun to work.