I am getting a recurring problem within Outlook 2010. It seems to happen for a few days and then things return to normal.
Here is the scenario:
1. New email arrives in inbox in BT Yahoo online.
2. F9 in desktop MS Outlook 2010 to Send/Receive mail.
3. New email arrives in Outlook Inbox - this new email is always an email which I received back in April 2012 and which has been deleted from my Outlook and is not the new email at 1. above. If there are, say, 4 new messages in Yahoo then my Outlook Inbox will contain 4 copies of the same April 2012 email.
This has happened 3 or 4 times the past few months and each time happens for a few days and then things revert to normal. The old email did have an attachment and I wonder if this has something to do with the problem. Presumably my .pst file is corrupted but I don't want to lose my contacts and email history.