With incoming emails to my @tmo.blackberry.net address (on BIS), are they kept on a server somewhere if I choose to delete them only "On Handheld" instead of "On Mailbox & Handheld"? If so, how long are they kept?

In the olden days, I could access my @tmo.blackberry.net mailbox from the web (BWC?), but that feature went away some time back. I was just wondering if I have this huge amount of disk space allocated on one of RIM's or T-Mobile's servers with all of those emails that I didn't delete "On Mailbox ...".

BIS 2.0 does not have a fixed mail box size and it has an autoaging feature of 30 days.

Thanks! Appreciate the explanation. It seems like they should not even give the option of deleting on just the handheld, though, if there is no way to access the messages during the 30 day aging period.