Random Email From EDad

I am LC with EDad and have been NC for 2+ years with NMom. I just randomly got an email from EDad, for no apparent reason:

"throwaway7483673,

As you know, your mother and I have been working on improving our marriage. This past weekend we renewed our wedding vows at a private ceremony. Thought you'd like to know. [Dad]"

Attached is a picture of them standing in front of a wedding cake at some place. I hadn't seen my NMom in 2 years, was very proud of it, and now my EDad sends me an uncalled for photo of them and now I've seen how she looks. I didn't like this and I'm kind of freaking out.

How do I respond to this, if at all? I know it seems like a minor thing but I'm kinda freaking out here, as I normally do when this stuff comes in.

EDIT: I tell him to "refrain from sending me emails of this type in the future" and he just asks me "why?" I don't know what to say.