It made me laugh that it came in Norwegian, but I really laughed when my son told me it was actually in Swedish. No, he doesn't know why either. Anyway, Google Translate renders it thusly:
As of Tuesday, May 29, all Norwegian's international departures and arrivals will move from Terminal 2 to Terminal 5. All domestic flights will continue to depart and arrive in Terminal 4 as usual. Welcome aboard Sincerely Norwegian Many benefits - always the same low price
And there's an icon down at the bottom of the e-mail telling me that they have free wifi on the flight. Sweet. The flight's only a couple of hours, but it's still sweet.