While downloading emails from your email account, sometimes Thunderbird shows a blue circle spins all the time in the background. It will continue for 10 to 15 minutes, after that Thunderbird’s performance will get slow. Sometimes it stops responding and you won’t be able to do something.
How to Fix Thunderbird Email Keeps Spinning Issue?
The main reason for this issue is that you are having tons of emails in your respective email account. Please check your email account and mailbox folders. Sometimes thousands of unwanted emails are there which the user forgets to delete. These emails are also synced with the Thunderbird and take too much time to load.
You should delete your unwanted emails from your email account. Or you can select only the specific email folder to sync with Thunderbird and uncheck the useless folder. The more and more time Thunderbird takes for synchronization, the blue circle will keep on spinning.