Yeah, that line didn't make any sense.  Her "tracking" does not use
read receipts.  A radioactive tracer, perhaps?

"Everytime someone from the same email ..."
Hmm.  Maybe that means everyone that was a recipient of an e-mail.

"... appears to be tracked ..."
Appears?  Wouldn't the OP want a sure indicator?
Tracked?  Still don't know what that is (because read receipts are
out).

"... if I save the mail"
Save it where?  She already has it in her Inbox for her to even know
about the e-mail.  If she is saving an e-mail to a .msg file on the
hard disk, it is outside of Outlook.  That means Outlook can't do
anything about "tracking" anything for the e-mail content within that
disconnected file.

The best rephrasing of her sentence that I could come up with was:

"If I save the e-mail, I want every recipient tracked."

But that doesn't help with defining "save the e-mail" and "tracked".