Of course it is slower. Thunderbird waits for gmail to confirm they have send the mail. Gmail webmail closes everything like as if the mail is sent and waits 10 seconds before even trying to send the mail (the undo send message time as email actually has no undo for sent mail.)

"Of course it is slower", is a bit HI-brow Matt, but I will take it as you are willing to help.

I have used Thunderbird for many years now, maybe 18 or 20. I do know about the pass through. All I am saying, when I hit send, there is about 20 to 40 seconds that I can not use my PC. This began about two weeks ago and is quite different than normal.

20-40 seconds is a detail which puts a finer point on it.

What happens if you start Windows in safe mode?

Not sure if I even know how to start in safe mode, and also not sure what this might accomplish. All was working fine until a couple of weeks ago, been using Thunderbird for lots of years. Thank you for responding Wayne. Gary Fiske

https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

Same problem email send very slow since about a week ago

Same problem email send very slow since about a week ago

Same process - start with Windows in safe mode. It's at the top of a longer list at https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems