BlackBerry :: Email Cache Hacked

I am trying to figure this one out. Can my Blackberry be hacked.My husband recently received a spam email that appeared to be from my yahoo account. The interesting part was that the other names on the "sent" to list were other email contacts of mine. That's fine but I don't keep a contact list on Yahoo. And I have 1000's of contacts in outlook.The mailing list on this email was much more selective. When I examined my blackberry, the emails that are currently cached in my blackberry were the only email addresses used in these spam email distribution lists! So it looks to me like my blackberry emails currently on my blackberry were somehow hacked and the addressed extracted from these emails alone.is this possible?? there were only about 10 email addresses in this spam email. And there was no record of any "sent" spam messages inside my Yahoo account. So it doesn't look my yahoo account was compromised