Do mass emails take up storage on the Exchange server once or for each recipient?

Question

The title pretty much sums up my question.

If a company administrator, or anyone, for the matter, sends a mass email to All employees, does the email message take up space for each user that receives it or just once on the mail server?

For example, say a 1MB message is sent to 1,000 users. Does this message take up 1MB of space on the server (it is stored just once) or 1,000MB (it is duplicated for each user)?

Answer 1

In Exchange, the message is stored in a single Extensible Storage Engine (ESE) database as a single entry.