Hi,
You can set up filters on your email account to help with this problem. Follow the instructions at the following help files found at http://www.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB11138&sliceId=SAL_Public&dialogID=194544884&stateId=1%200%20194540744 and
http://www.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB10981&sliceId=SAL_Public&dialogID=194544884&stateId=1%200%20194540744 and
http://www.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB11056&sliceId=SAL_Public&dialogID=194544884&stateId=1%200%20194540744
Hope this helps,
Doc