Email notices at this point in the game still not treated the same in courts as real on paper notices when it comes to being able to prove that it was sent and they got it. Sending written notice using confirmed mail delivery and keeping a copy for your own records stapled to your postal receipt can give a court something more solid to back your claim up that notice was sent. using Email or even regular mail will not give you a paper trail to prove something was sent and with the post office and the courts my experience was that the courts wont allow a tenant claim of not getting notice via unsigned method when there is proof it was put in to the system. If you really want to make sure there is no issue then you send out one additional copy of the notice a couple days after or via different method like say fed ex. Complete reliance on Emailed notices can bite you back since all it would take is one tenant in a court room claiming they never got the notice and you don't have a provable trail so you would have to start all over paying how many hundred again to re file ?