It is often necessary to find the overall amount of storage used in EMC EmailXtender.
In order to find this out use the following SQL:
SELECT COUNT(distinct EmailAddress.EmailAddress) AS [No Archives], COUNT_BIG(Route.MD5HashKey) AS [No Messages], ROUND(SUM(CAST(Message.MsgSize AS REAL)) / 1024 / 1024, 2) AS [Total Size MB]
Route ON EmailAddress.EmailId = Route.EmailId INNER JOIN
Message ON Route.MD5HashKey = Message.MD5HashKey AND Route.TimeStamp = Message.TimeStamp