You'll have to go through the email set up again and it should be fine. As for marking them is read on your email then can't help you out. The only thning I can think of is not to open it on the phone and just wait till you get online to read it
Posted from my CrackBerry at wapforums.crackberry.com
The other thing you cuold do if after you read it on your BB mark it as unread ( options, unread) then delete from handheld only. That would leave it as unread on your computer and get it off you BB ( memory is so important.) I want a way to flag my email on my bb so that if I do not have time to respond at the time I read it I can later remeber when I see the flag.