Do you host your email on popular email hosting services like Yahoo and Gmail, or do you host it on your own server? I think for business correspondence, it will look more professional to use yourname@yourdomain.com than to use yourname@yahoo.com.
I would love to have and use an email address like myname@mydomain.com. I do have some actually, as my web host allows me to create unlimited email addresses @mydomain.com. But it's not so practical for me to open my inbox there. It needs more clicks and the webmail also loads slowly.