Email Communication After Password Change


New Email
Hey everyone, important question that i cant seem to find the answer for ANYWHERE. Please bare with me and any help is appreciated.

On thunderbird (or even any of them just speaking from experience on thunderbird) .

Lets say i am logged into my email account on my thunderbird. If i change the password for my email account, how is it possible that i still get emails for that account? Not all the time and not for a long time but lets say if my password is changed, if i just leave thunderbird alone and not constantly refresh or mess with it, I still get my emails. Usually a few emails come in then i get the popup to update my password but what causes those few emails to come through? Im very curious as to how this happens.

Thanks everybody