Note: This Q is specific to gmail, Thunderbird and IMAP. (It is similar to, but more specific than, this older, and more general question, about gmail access, but with an unspecified email tool and protocol. Also it appears it might be related to this Q.)
Why does all incoming email into Thunderbird, via IMAP from my gmail account, now, suddenly no longer show up in that account's
Inbox for my gmail account, but rather, only gets put into the
All Mail folder there?
To be clear, the email is being delivered, just not to the inbox.
I've been successfully using Thunderbird to access gmail with IMAP for many years. Suddenly it broke without me changing anything. Note: I have seen some Thunderbird security updates recently, so I'm not pointing any fingers, just trying to find a solution to this.
If I login to Google's gmail web page, the very same test message is in their
Inbox. In fact, the test message is showing up in both their
All Mail folders.
Settings there, i.e. click the gear, then click 'See all settings', shows that I don't have any filters, nor any forwarding.
(BTW, by default they don't show the
All Mail folder, but you can turn it on with Gear | Settings | See all Settings | Labels | All Mail | Show.)
I'm running: Thunderbird v68.10.0 and FireFox 78.0.2, on GNU/Linux Debian Buster 10.4.