in short...no.
unless your getting emails straight to your *@*.blackberry.net address.
if not...the e-mails are as safe as the POP3 accounts you're pulling them from.
The best method I have found Juicy is to do a forward on your POP3 accounts straight to your
[email protected] account. That way you will get them instantly and not have to worry about pulling them down through blackberry web client.
I do a forwad to my blackberry email address AND leave the pop3 inbox as kind of a backup.