what difference does it make having an IP address or not. it's not hard to get one. you can make a 1x1 pixel image host it on a site, write an email w/ html <img src="http://site.com/picture.jpg"> check logs for that image being downloaded. Check email headers, there's tons of ways. I don't see any harm in giving ways to obtain an IP address.
if you can't get an ipaddress you're probably not skillful enough to make use of the knowledge even after you have one.