Question

Say we have a user [e-mail] which sends an email to user [e-mail]. Then, user [e-mail] forward the email to [e-mail] and [e-mail].

Giving that it was the same email, does the exchange server keeps 4 different copies of the email data or it simply points the users to the same email (only with different headers)?

if user [e-mail] adds a simple line (or more, it does not really matter), but keeps the older email data intact, does the exchange server keeps a revision history of that mail and sends only the delta, or it simply builds a whole new email for [e-mail] and [e-mail]?

Answer 1

Giving that it was the same email, does the exchange server keeps 4 different copies of the email data or it simply points the users to the same email (only with different headers)?

Regardless of any of your specific requests, each email sent is a new email (all new header info etc, is all part of an email). If you send 1 email to 30 people (all on the same exchange store) there is only 1 version of the complete email in the system and 30 links to the email for each of the 30 people. Attachments are also stored this way.

if user [e-mail] adds a simple line (or more, it does not really matter), but keeps the older email data intact, does the exchange server keeps a revision history of that mail and sends only the delta, or it simply builds a whole new email for [e-mail] and [e-mail]?

I’m not sure about revision history, but again any email sent is a new email and regardless of exchange stores, is sent in it’s entirety. If fordwarded email contains an attachment and the recipient is on the same exchange store, exchange will not duplicate the attachment.

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