Some clarifications please.
a) What is a SBE Domain controller ? Is this Small Business Server ?
b) Does that mean you migrated from SBS 2003 to Windows 2008 + Exchange Server ?
How did you remove the previous domain controller from the domain ? Did you use DCPROMO ?
How did you remove the previous exchange server ?
Did you follow this ?
http://technet.microsoft.com/en-us/library/bb288905(EXCHG.80).aspxAttached screenshot of mail queue ? Does this stay there always ?
do you have some kinda solution to prevent backscatter, directory harvest type spam attacks
Let us know about what steps you did.