Hi Rashers
On the Alerts tab, enter 7700 and any other Squawks you want into the Squawk box (one per line, and make sure there isn't a blank line anywhere, especially at the bottom of the list). Then make sure the Squawk header is ticked.
Then tick the Send an Email box and enter your email address in the box beside it.
BTW there's a box at the top left of the Alerts page that you tick if you want alerts from the network as well as from MyFlights.
That's it!
HTH
Rod