This folder cannot contain messages

Evolution seems to reset my inbox about twice/three times a week so I
cannot see my mail.  Here is the setup.

All files are local except the inbox; in box is defined as my company
name and it setup as a imap account.  it works fine most of the time
except when something really important happens and I need my email
quickly, then, mysteriously, this folder cannot contain messages.  what
am I doing wrong, or what do I need to do so that Evolution works
properly?