First, this isn't about anyone in particular. I get lots of evites.
I don't like evites. I dont' like evite.
- Evite messages don't say where or when the event is.
- Tracking whether I read the actual invitation is creepy.
- The way evite sometimes hides who sent the message obnoxious
- I've gotten spam on addresses only evite knew about. Conclusion, using evite supports spam.
- Once you've given evite my address, you can't ungive it.
World: Dont' use evite please, or if you must, please don't give my real email address to them.
In general, handing someone else's email address over to advertising-driven agencies is not OK. Most people would not consider doing this in the general case. Evite is not a special case.