This may be a stupid question, but I am not an expert with DNS yet. I have created a new website for a client that I would like to host with Heroku. The client has registered their domain with Network Solutions, but the NS records are pointing to BizLand hosting. They currently use BizLand for hosting their website and email. I would like to preserve their email while switching to the new host. I need to add a CNAME record to a www subdomain in order for their website to switch over to the new host.
The problem I'm having is when I log into Network Solutions (the registrar), it does not allow me to edit the DNS records without moving the Name Server records to Network Solutions. When I log into BizLand (the host/name server) it does not allow me to edit the DNS records because it is not the domain registrar. I would like to get away from these two companies altogether by transferring the domain to someone like DNSimple for easier DNS management. My question is: how can I do it without disrupting email service. I think I read somewhere that the MX records would reset once the NS records changed to a new provider.
What do I need to do in order to make this switch and keep email working?