In godaddy I have the name servers pointing toward my server. Then I use mx for mail then point A records to another IP(server) that host the actually website. We are switching that but they want me to add a cname and A record. my question is will it mess up my email MX? what does adding cname actually do?
A CNAME is just a routing rule and shouldn't affect your MX as long as they are different, i.e. the CNAME is something like blog.mywebsite.com and the MX is something like mail.mywebsite.com.