If any of you have played with the beta version of exchange 2010, you can find that the default database that gets installed as part of the mailbox role has a random number added to the database name. For example, my database name is “Mailbox Database 0369105121”.
Nothing! It is a random number given to the database name to make it unique in the exchange organization. Unlike the previous versions, there are no storage groups in 2010 and mailbox databases are an organizational entity. Hence, you cannot have duplicate names for mailbox databases.
In 2007, you can have the same database name for more than one mailbox database as long as they reside in the different storage groups, even on the same server. The database name is uniquely identified by a combination of server name, storage group name and the database name itself. But, the database name is identified by its name itself in 2010 and hence the attempt to make the name unique by adding random numbers at the end.