Originally Posted by mike_v
We were having this exact issue. It all stemmed from the "send as" permissions for the BESAdmin account. I thought I had all the bases covered with adding the BESADmin send as permissions at the domain root level. However, for what ever reason the permissions did not filter down to certain OU's. Double check the individual security settings for each BB user and make sure that the BESAdmin user is listed in the security properties. After you do that, you have to shut off the BB router service for 20 min, so the cached security info clears. After that all will hopefully be well. Hope this helps ya.
is this applied through active directory users and computers?
I have tried this and I have checked the effective permissions and it says that it has send and receive as permissions but I'm still getting the same error message.