Email: "You're Invited!!!"

I got this in a separate email. Oddly enough, there was no email address listed. But this seems to be an invitation to something. I hear Marillion. I like Marillion. I hear Skye Blue doesn't want me going to this. Skye Blue has been antagonistic so far, so.. this is probably actually a really good thing for me to go to.

The question is, when is it, where, and with whom?