Cant access and email address from my domain (shopify store)

I have a major issue with my email I cant access any emails linked to my domain. My host advised me to update nameservers but this forced the site to close. The email started working fine but the site went down. So there is an issue somewhere either cpanel, Domain host or shopify that it not allowing me to access any emails addresses linked to my domain [login to view URL] I have had the hosting account ten year and have many sites under my reseller account also shopify that have always worked but this new domain registrar is making life very hard. Should be an easy fix for an expert looking to pay $30 plus $20 bonus if fixed now immediately should take less that 30 minutes