Strange Behavior

[nyrainman]

All has been working well except for the past few weeks, whereas when I mark an email as read or add a star, then reopen Thunderbird a short time later, the star is gone and the email that used to be mark as read now shows again as unread.

This is driving me crazy because at times it seems new email was received, but in reviewing all my mail, that is not the case. Thunderbird somehow keeps changing read mail back to unread mail and no its starting to change what I've marked with the star.

I have the latest version and am running Win10.

[DanRaisch]

How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.
http://kb.mozillazine.org/Thunderbird_: ... ng_Folders

[nyrainman]

All my accounts are IMAP

Note: I just checked my accounts and the same email again showed as unread and the star was gone. This is the second time with that particular email.

[DanRaisch]

Right click on the name of the folder in which those messages are reappearing as unread. Select "Properties" from the context menu and then click on the "Repair Folder" button.