Thundererbird automatic log out option, especially on android

[shoi]

When you don't remember the password (or, more to the point, when someone steals your phone) the website will send an email to enable you (or the thief) to get back in

(I have one email address for my phone, my main address is via fastmail and TB)

If I don't use TB for a short period of time I would like it to log out, so the thief cannot get access to websites which I care about enough not to have saved the PW.  Like banking websites do

That's it. 

(I've tried a load of email clients, I can't find one which does this)   I often remember to log out expressly, but not always

[Jon]

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