Mail Deletes emails before they can be read

When is Apple going to fix a long standing problem with Mail?

I''m really irritated and exasperated with emails disappearing before I can read them. Some come in and in a flash they're gone. I search the Junk and S[am folders and there's nothing to be found. Today, I'm trying to re-set a password and the bank has sent an email and it disappears before I can read it. So far, it's happened 5 times!

I've deleted and re-installed the app so many times and I'm tired of it.

[Edited by Moderator]