I forgot to suggest that you first log out of all open Fastmail sessions (except the one which allows you to see the logins). I’m not sure my earlier suggestions are all that useful unless you clear all saved logins and cookies.
But before going through that trouble, I have a few more questions.
- When you finish reading you email, do you leave the browser window open on your Fastmail account?
- Or do you just close the browser tab or window?
- Or do you use the Fastmail log out feature?
- When you say you must log back in, do you mean you have to re-enter your password? Or something else?
- If you just leave the Fastmail browser tab open (with the PC set to not sleep), what do you see? Does the Fastmail message list just disappear (due to something logging you off)?
I use two-factor authentication and choose to trust the device, which sets up cookies so that I don’t have to re-enter my password on that device unless I log out.
Bill