Package: thunderbird Version: 1:60.7.2-1~deb9u1 It can happen that Thunderbird is not showing you any error messages and yet also not getting any new messages.
It was the case for me, when my email server partially broke (maybe due to debian 9 to 10 upgrade) and was in some way not agreeing with Thunderbird client on the TLS version to use. Then automatic downloads of new emails, and also manually triggered downloads - show no errors. Also, selecting a folder and choosing the button to repair folder on it - results in all messages disappearing from it but nothing shows back and no error is shown. you have to go to debug tools, or shift+ctrl+j to see errors console, there it was showing: Error code: <a id="errorCode" title="SSL_ERROR_PROTOCOL_VERSION_ALERT">SSL_ERROR_PROTOCOL_VERSION_ALERT</a> This error here is about the fact that this kind of errors are silent. (The SSL started working again after some work on the email server, so I assume that was not a bug in thunderbird).
