Tape Backup on SBS2003
Someone asked why the built in Backup is taking up more tape space than what would be expected.
This KB deals with your issue: Backups on Windows Small Business Server 2003 may use more backup media space than expected:
http://support.microsoft.com/default.aspx?scid=kb;en-us;840754
You should look at using the command line switches specifically designed for Exchange.
HOW TO: Use Command Line Parameters with the Ntbackup Command in Windows Server 2003
http://support.microsoft.com/default.aspx?scid=kb;en-us;814583
How to turn on the Exchange writer for the Volume Shadow Copy service in Windows Small Business Server 2003
http://support.microsoft.com/default.aspx?scid=kb;en-us;838183