07-11-2009, 01:59 PM
Join Date: Jan 2006
Carrier: Rogers CA
Post Thanks: 20
Thanked 77 Times in 68 Posts
If you are sure it is your Blackberry check for suspicious software (something you installed just before this started would be a good candidate). Options -> Advanced Options -> Applications will give you a list of applications installed on the device. You may also delete them here. If you can't find anything, and are really sure it is your Blackberry, wipe and reinstall the OS but don't reinstall 3rd party applications.
However if, as you imply, the email are only going to members of your yahoo address book, and not those in your Blackberry contacts I would suspect your yahoo account has been compromised.
My other Blackberry is a PlayBook.