How Microsoft Exchange manages attachments sent to multiple users?

Scenario:



Suppose all users below are using Microsoft Exchange Email Server. Mr. A sends an email to all users with an attachment. Does Microsoft Exchange store one copy of the attachment on the server and link to it, or does it duplicate the file and place it in all the users mailbox space?



So if the email has a 1MB attachment, and it is sent to 100 users, the server will have 100MB used by the attachment or 1MB?How Microsoft Exchange manages attachments sent to multiple users?If the users all have their mailboxes on the server, then the server stores one copy of the attachment. Users see the link to it in their email and can download it from the server, even though it seems like it's attached to their mail.