I have a basic/n00b question regarding how messages/attachments are stored in the Exchange database. If I send out a mail message with a 1MB attachment to 10 people (all on the same Exchange server) will the messages/attachments consume 10MB+ of storage space or only 1MB+ of storage space (includes pointer overhead)?

It depends if the users are all on the same database or whether they are spread across multiple databaes on the same server. Single Instance Storage is per-database, so if the users are all on the same database then there is only one copy of the attachment and everyone has pointers to it. If the users are spread across databases, then each database contains a copy of the attachment. The transaction is also recorded in the transaction logs for each database that the message is sent to, so, for a while at least until they are purged by the backup process, the transaction logs also contain the data.Neil Hobson, Exchange MVP

On Fri, 20-Nov-09 03:48:51 GMT, Jack Calkins wrote:>I have a basic/n00b question regarding how messages/attachments are stored in the Exchange database. If I send out a mail message with a 1MB attachment to 10 people (all on the same Exchange server) will the messages/attachments consume 10MB+ of storage space or only 1MB+ of storage space (includes pointer overhead)? That depends on which release of Exchange you're running, and whetheror not the ten mailboxes are all on the same mailbox database.server -- unlees there's just one database on that server):Exchange 2003 - Only one message (with the attachment) is stored.Exchange 2007 - Ten messages are stored, but only one copy of theattachment.Exchange 2010 - Ten messages and ten attachments are stored.---Rich MatheisenMCSE+I, Exchange MVP--- Rich Matheisen MCSE+I, Exchange MVP