i am having an issuse with my email disappearing after its read and i leave the inbox and go to another folder. If "Read" Emails are left in the "Inbox", then I leave that folder, move to another folder, and return to the "Inbox" only "Unread" emails are visible. All the "Read" emails previously in the "Inbox" have disappeared - I can't find them in any folder what is happening i cannot figure it out? it only does it one 1 email address. i am running MAC osx yosimite 10.10.5 and thunderbird 52.3.0