Hello, A couple of days ago on my Windows 10 PC, Thunderbird automatically updated to 78.2.2. Since then it won't receive new messages. Nothing wrong the server end (Fasthosts), and they've checked that I'm using all the correct incoming/outgoing settings. If I go to webmail I can see new messages that aren't appearing in Thunderbird. Windows Mail app also shows new messages without a problem. This little spinning circle thing in the Inbox tab continually spins (see image below). When I send messages, they send but I get this message: "Your message was sent but a copy was not placed in your sent folder (Sent) due to network or file access errors." Thank you, Martin P.S. I have Zone Alarm (Free) Application Control Settings set to trust (green ticks) all inbound and outbound activity of all the Thunderbird programs I could find. I also use Avast Free Antivirus.