I'm normally in the 1.5GB range. I've had some rare issues of high CPU, sometimes but more rarely with high memory.

Are you able to start Thunderbird in troubleshoot mode?

I thought we had an open bug report for Mac high memory usage, but they are all closed https://mzl.la/47Q8bEZ

Do you have any newsgroups defined?

I'm normally in the 1.5GB range. I've had some rare issues of high CPU, sometimes but more rarely with high memory. Are you able to start Thunderbird in troubleshoot mode?

No I only have the option to open.

I thought we had an open bug report for Mac high memory usage, but they are all closed https://mzl.la/47Q8bEZ Do you have any newsgroups defined?

No newsgroups, just a new user who has a problem, Mac-Forums suggests it could be a memory leak, but I do not know what that means.

I also have high memory usage, 1.5gb on macbook Sonoma 14.5. Any update/fixes?

I also have high memory usage, 1.5gb on macbook Sonoma 14.5. Any update/fixes?

Fortunately, John, your memory usage is nowhere near the OP's.

My advice is to see what happens with version 128 which comes out in July. If it's not better then create a new question.

Wayne Mery said

I'm normally in the 1.5GB range. I've had some rare issues of high CPU, sometimes but more rarely with high memory. Are you able to start Thunderbird in troubleshoot mode?

No I only have the option to open.

https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird