Just switching between inboxes can cause up to a 10 second delay with Thundebird "not responding" with the spinning wheel. It has been like this for the last few laptops I've had and through all the updates and I am getting ready to call it quits. I did a performance recording of me just clicking through the different folders and then it locks up on one. You can see it here https://share.firefox.dev/3WlrRi9 I am using a primary gmail imap account, an office 365 imap account, and another imap account from an ISP. On Win 10 LTSC, CPU: 16 x 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz @ 2304 MHz 10240 KB Cache, MEM: 65277 MB, 60% (39120 MB) free, GFX: NVIDIA GeForce RTX 3080 Laptop GPU 16192 MB