This is what I have done for the company I work for...We started getting the problems in Aug until now (Oct)...also Bell Canada is no help at all.
Because of the upgrade from BIS 1.8 to 2.0...they didnt merge the version right...so any email created with version 1.8 will get those problems using version 2.0.
You need to create a new email...if you delete the current blackberry email address...it will not be deleted until 30 days from the RIM servers.
< thats for Bell Canada Users
Change it to:
Just doing that it works...if any provider tells you that its a spam filter or your service book on the handheld is out of date...HANG UP THE PHONE...
Just making that small change...EVERYTHING is back to normal...