Mail view often freezes

Dear Forum,

My Mail app often does a type of freeze.

If swapping between accounts/folders [neither one is more or less prominent than another, its more the change of the view] the list of emails doesnt change. So if i am in one folder with all the emails, and i highlight another folder, the list of emails doesnt change, it still shows the last list of emails. The Mail app is exactly frozen as i can navigate other folders etc, but the email list does no change or update. If i leave the app eventually it comes back to life and shows correctly.

Any ideas what could be causing this?