E-mail frustration with Telkom

I have had intermittent problems with my Telkom emails for about two weeks now. Some days I can send emails, other days I can receive. Our connection is dsl, but it gets disconnected time and again. Contacted Telkom, numerous times, even had a independent IT person take a look and investigate what the problem was. It is definitely on Telkoms side. I just cant seem to find a call center agent that is willing to help me resolve this issue. I think there is a port number/server setting that is not correct.