I'm sorry, but no. There are so many private servers out there it's hard to keep track. If this was the case, Gravity would of done something to all private servers (or at least majority of them) or even shut down eAthena, rAthena, Hercules, rAMod, eAMod, brAthena, etc.
Also, as Mootie pointed out, people should stop providing services then for private server owners since now you're labeled as an acquaintance towards specific servers you work(ed) for.
These emails are false until otherwise proven factual with actual proper grammar, logos, real business addresses, etc.