Outgoing Emails with Google Channel not being sent - Possible 2fa issue?

Infos:

  • Used Zammad version: 5.0.2-1637576537.10be8dab.focal
  • Used Zammad installation type: package
  • Operating system: Ubuntu 20.04
  • Browser + version: Chromium 96.0.4664.45

I had previously set up a traditional email channel (for a non-Google email) to test configurations and today I updated Zammad to the latest version available, removed my previous test email account, closed all tickets related to that account, and then added the Google channel and linked a specific email account to it. I then reviewed all my groups to ensure they would send from that account

I am now able to receive emails into Zammad (so inbound is working) however all replies to tickets by agents are not received by the end users in our testing. When checking the sent folder for the Google account, the replies are not visible there either.

Looking at the Zammand production.log, nothing seems amiss. There are no errors or warnings of any kind, the ticket being responded to is visible in the logs, the template renders, etc.

Expected behavior:

  • Reply is received by the other party to their inbox

Actual behavior:

  • No reply is received by the other party

Steps to reproduce the behavior:

  • Use a Google account with 2FA enabled, create a Google channel in Zammad, send an email to that Google channel, reply to the ticket created by that email, wait for response on the other end indefinitely.

How I resolved it:
I was able to get around this by removing the Google account altogether and creating a traditional email channel along with generating an app password from Google to use for authentication. Once I did that, both incoming and outgoing emails worked perfectly.