No emails. If there is any chance you will ever regret sending something like that--don't. Love letters to someone you love & trust are one thing, but to an ex? That is just putting your heart on a plate and giving her a fork & knife to eat it with.
If you *must* have closure, do it with a phone call. If she won't take a call from you, then sending an email is the same as forcing yourself on her.
Remember: Words spoken are gone like the wind... words written are forever.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh