So I wound up deleting the email and not responding. A few things mentioned here really made sense, as well as a few things that others have told me.

Ally is particularly right in that I really have no emotion towards her. I'm very happy where I am with my life right now. I don't need whatever drama or negativity that my ex would bring. Plus, there's no sense in keeping contact with someone who was undoubtedly shitty to me.

Part of me thinks there's some ulterior motive for this. There's no logical reason to reach out to an ex after years. Part of me hopes she's doing alright and in a good spot herself. One of my friends suggested the idea that maybe she's doing it as part of a rehab thing, but it's been years and I don't know.

I don't have the anger that I once had towards her, in fact I really feel nothing towards her. I get more mad at myself for not seeing enough of the signs and for not listening to my friends who were really trying to look out for me.

So long story short, I did nothing. Well that's not totally true. I had a bunch of beers and really stunk it up on star wars battlefront. Other than that, no contact with the ex whatsoever.

Thanks for the advice guys.
Yoko, it wasn't hurricane. She's a story for another day, and both Tammys to my Ron Swanson.