I run Outlook 2007, normally without incident. But a year or two ago I had reason to log onto to my ISP-provided webmail facility and noticed that there were several very old emails there that Outlook hadn't downloaded. We never resolved it, and now, after another year or so, the same thing has happened again.

The ISP tech people tell me that the only thing notable about the emails that haven't downloaded are that they have an attribute of HDM (not sure what that means). I've had a search on the web, but can't find anything helpful. Any ideas, anyone?

ADDED LATER: I've now done an experiment. Closed Outllook 2007, opened Outlook Express v6, set up the same account in Outlook Express, checked mail and, lo and behold, the old emails downloaded!?!?! Which is interesting, but doesn't solve my problem, which is that I can't rely on Outlook 2007 to download all my mail. Any ideas gratefully accepted.