How do I prevent MS Exchange users from forwarding or copying a message sent via System.Net.Mail?

Question

Don't send the mail in the first place? Beyond that you're out of options. — rene, Aug 24 '12 at 21:46

score 1 · Answer 1 · answered Aug 24 '12 at 21:50

1

Not possible unless you write an Outlook plugin and even if you do, a determined user will always be able to do it one way or another.

answered Aug 24 '12 at 21:50

Icarus

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Yup. It's even harder to stop copy-paste or screenshots. – Austin Salonen Aug 24 '12 at 22:09

score 0 · Accepted Answer · answered Aug 24 '12 at 23:34

You can't. If the email message was sent via Exchange rather than SMTP, you might be able to...with a server-side Exchange plugin/extension. But if the mail is sent via SMTP and is outside the Exchange server, you're SOL. The mail message is nothing more than a simple text file. Which see RFC 5322: Internet Message Format.

Further SMTP itself is a store-and-forward protocol. Every mail server involved in moving the message from sender to recipients gets a copy of the message and can keep it around.

How do I prevent MS Exchange users from forwarding or copying a message sent via System.Net.Mail?

2 Answers2