Since April 1, Thunderbird has no longer been working with Avast One. All the solutions online (for older AVG and Avast) show going into settings, searching for a setting and exporting certificates to load into Thunderbird.
However, Avast One has no setting search bar or at least not one that is visible by default and no apparent way to export certificates.
Is there a hidden setting menu somewhere? Spent a long time on phone with support and their first option was for me to let someone tap into my computer to configure Avast instead of me being talked through the process... A definite no-go for me.
Tried adding the free premium trial to no-effect... no menu option appeared. If I turn off Email Guardian then email flows just fine, so it's not really a server or Thunderbird issue.