Compacting is done when WinMail is opened/closed 100 times. There is no
need to do it more often as the database structure is quite different from
Outlook Express and the DBX files. In Windows Mail, messages are stored
as *.eml and *.nws files and the only database is the index files to them
which uses ESENT (Extensible
Storage Engine Architecture). You can read more about ESENT here:
Extensible Storage Engine Architecture:
http://www.microsoft.com/technet/pr...Ref/764d8347-a99b-408a-a774-f1263797c3b0.mspx