Macbook and iPhone emails not syncing; old emails won't delete from MacBook

A few months back, I started to have the random email in my MacBook Pro Apple Mail "stay", even after it had been deleted from my iPhone Apple Mail. It happens very inconsistently, but at this point I have about a dozen emails (only on the MacBook) that won't delete. They're "browned out" in the inbox, and if I try to delete them I get a message that it cannot be removed because "the specified object was not found in the store. The process failed to get the correct properties." How do I get rid of these emails and get my systems properly synced? Many thanks in advance.