If so you could be loosing out on important emails without even knowing. Just think - what if buyers are contacting you about a listing and you never receive that email? Chances are the buyer won't contact you a second time and probably won't call you. They will be under the assumption that you don't care and will move on to the next Agent. Free email providers such as Yahoo, Comcast, AOL and others will block email at their discretion and you won't ever know that the email was blocked. See http://www.ahfx.net/weblog.php?article=107 for a post about this. As you can see from reading this post, people have been having these issues with Yahoo since 2006.
Does Yahoo have the right to block your emails? Yes - it is their servers and they are offering the service for free. So when I hear people complain about not receiving emails in their Yahoo (or other free) email account, I simply say "You get what you pay for". I suggest purchasing your own domain name for $9.99 per year from GoDaddy or other domain provider and setup your own email accounts under your own domain. GoDaddy allows you to register a domain for $9.99 and setup 1 email account on that domain for another $9.99 per year. That's a total cost of $19.98 per year. Heck just imagine how much business and $$ you are loosing by staying with a free email provider that may be blocking your important emails. The way I see it is you can't afford not to do this. Plus it looks more professional when you send email from your own domain.
Misty - the other side of the coin is the people we are communicating with. If someone has one of these free email sites (or any site for that matter) we always tell them to add our address to the email they want to receive - and also to check their spam, though that doesn't help if our email to them is blocked at the server level.