I guess everyone has a different outlook on the subject. Some prefer to get to know some things about the person thru emails and phone calls before the meeting. I myself prefer personal emails because it gives me the option of seeing what I have sent and what was said. You don't get that with EH messages. A separate email is a good idea. If you don't like them having your phone number just get one of those throw away cell phones and use it specifically for your OC calls.