Reinstate my email

I have an issue with my email not working and I need to get it re-instated. My website is on a Wix server, however the domain and hosting is elsewhere, I imagine this may be the problem but not sure. What would you need to be able to get the email up and running again - would you need the details of the hosting platform; where the domain and email is registered and would you need things like MX Records, TXT Records and things like that. What would be required.