Recently, within the past week, I have added Exchange 2007 to our Exchange 2003 organization. I started the migration by moving our IT staff to the new mailbox server for testing. EDB file size on 2003 was about 40GB. After three days on the 2007 mailbox server our new database EDB has grown to 83GB. Has anyone experienced growth like this? There is no way we are receiving that much mail or mail with attachments on a daily basis. Any help would be greatly appreciated. Steven Shock Systems Integration Manager

I would guess you have a mail looping. Check your trackick logs and SMTP logs to get more info

Best resource I've found on this: http://blogs.technet.com/b/mikelag/archive/2009/07/12/troubleshooting-store-log-database-growth-issues.aspx