trace (spy) outgoing traffic

[oilaripi]

Hello, Is there way to trace, spy, every outgoing send message on mozilla. What do I mean. I want every single letter sent by a user, a copy of it to go to a specific address. But I do not want the user to know. I tried with the BCC(Copies and Folder BCC these email address ), but when I add an address, it is visible in the new message form(BCC field). I want to hide it. I accept any suggestions

[trolly]

Wireshark

And your intention is probably illegal.