[Thunderbird/IMAP] All new emails being listed as read?

[Turtle]

So I tried searching on this issue, but my searches were bringing up way too many other problems since the search phrases were too common across it.

Basically, I've noticed that on my IMAP email through Thunderbird, all messages are being marked as Read, even the newest ones that I haven't looked at. I don't even get a notice when new emails arrive.

The problem is annoying, but not dire. I'm not losing any email that I can tell, but I have missed some time sensitive emails since they appear read.

Since we're on the subject, anyone have recommendations on email software? I'm thinking of switching away from thunderbird since due to work I now have a lot more emails to work with.