Zoho emails with domain name have been set up and were working but can not not be accessed

Zoho emails with domain name have been set up and were working but can not not be accessed

We have about 20 zoho email addresses for our domain name@thesharkstail.com and for some reason we can no longer read or access our emails. 

They were working before but we think someone has accessed either our godaddy domain account or our zoho account and changed something that is now stopping them from working.. 

When I try to set up access via a external client (Mac Mail or Gmail on my andriod phone) it does not read or see the zoho account,.