Unable To Send/Receive Emails On A Telkom Network

I logged a call two calls with *** & *** to assist me with our domain madikizaindustries.co.za not working on their internet for some some reason. We are struggling to send/receive emails, MS Outlook 2016 only works when we connected on a different network. We cant do much without the email, Telkom consultants said the server techs will call me and its been 3 weeks now having the same problem