I'm running Outlook Express at work to read my POP mail. Throughout the day I'm reading messages etc. in OE. I've set TreoMail to only download unread messages. At night, right before going to bed I check my mail on the Treo. I find sometimes that it still retrieves messages I'm certain that I read during the day.

How is this happening? How does TreoMail make the determination as to read/unread? I imagine it is picking it up from my POP account. Is there some lag time between when I read something in OE and when it is marked as read on the server?