This sounds more like an issue with ATT's roaming software.

The Mlife service uses ATT's roaming WAP GPRS access point, and email uses the Blackberry access point. I know ATT had some major GPRS outages in the past days so perhaps that is related. Major cities like Chicago have been without Blackberry service since wednesday night. Some say it has to do with the Cingular/ATT combination as they loaded new roaming software wednesday night to allow all ATT users to roam on Cingular.

Your only real option is to have try and have the service book resent to the device, perhaps something got corrupted in it.

All in all it just comes down to ATT's pretty poor performance at the moment.