with BIS,

say you receive an email on your device and you are sitting at your computer and read the email on your computer.

Will it change to "read" as opposed to "unread" on your device.

Under IMAP accounts and such as Yahoo, Gmail accounts, yes.

Routine POP email accounts do not reconcile "read" emails.

This does not work for me on Imap bis. If i read it on the computer it does not sync to my phone. I have only let it sit there for 30 minutes to test but i received mail in that time to and it never got marked as read on the bb.

When you mean your computer are you using a mail like Outlook/ThunderBird/etc... If so then Read/Unread will not sync..

They will sync you are using Yahoo and GMail is a bit flaky and takes time.. (Can't wait for BIS 2.6) But Read/Unread will flag from the Web Interfaces only.