I feel the best way to have a good email for professional/business purposes is to have your own domain and hsot it somewhere. Later you can even have your site. At present there are a few such services like Rediffmail Pro and Indiatimes Meramail. But none of them is too reliable.
I would prefer to register a domain name on my own using my own credit card. So that I control the domain name. Then pay for some basic hosting and use POP3 mails.
If you want free ones, there are loads of options. The recent rage being Gmail. It is free, provides POP3. But I am not sure that it will remain free and that too with POP3. BTW, if you have an always-on net connection, POP3 may not matter to you in terms of cost. But still its the most convenient way.
Other free POP3 service providers are *www.softhome.net, *www.hotpop.com, *www.yahoo.com (with the help of yahoopops form *yahoopops.sourceforge.net)