Trying to calculateExchange 2007 storage requirements for a 2003-to-2007 migration. Can anyone comment on the best way to accurately measure the following valuesin anExchange 2003 system: In megabytes, average weekly incoming email per user, including both external and internal messages Average message size Thanks in advance.

have you seen this tool? http://msexchangeteam.com/archive/2008/06/12/449007.aspx

Thanks knightly, I have seen it and I guess I could just use the values it provides for the various user profiles, i.e., light, average, heavy, etc., andthe average message size. But I was wondering if there's a way to measure these things more precisely for our organization, then use the storage planning documentation to manually calculate 'true' mailbox size. Since I posted this I saw some information on the Profile Analyzer, but haven't had a chance to try it yet. I'm hoping maybe that will provide what I'm looking for...? Thanks again.