BIS
Was helping a friend check her Blackberry BIS with Verizon today. Tried to login to Verizon's BIS email setup, but was unable to. We gave up, eventually, and I logged into my Sprint BIS to show her the filters I was able to set up to ensure that Gmail sent items didn't show up on my Blackberry.
When I logged in, I noticed that it asked me for my PIN and ESN--that was new. I figured it was something new, so I went ahead and input my ESN (the PIN was already filled in.) I didn't realize that the PIN entered for me was not my PIN. As a result, I accidentally associated my Sprint account with her Verizon Blackberry... and she started getting my emails. All my registered email accounts showed up on her BB Pearl. Awkward.
I logged back into Sprint BIS and moved things to my device, but the email icons are still on her BB's screen... So we're going to wait and see if she keeps getting my emails.
Interesting phenomenon. Moving email accounts across carriers and BIS accounts.