Need Info on Email Services

My office (20 employees) is not using Digex anymore and they were hosting our mail server.
I must find a cheap service, like yahoo, to create 20 pop emais using “employee@mycompany.com.” because they do not want to run an internal mail server.
Any info would be appreciated on services, such as yahoo, for this. My boss says I should be able to find something like this for about $1 per account.
Any answers?