This actually makes sense, since the CNAME does not only replace A records, but any record. Not just MX but your NS and SOA records as well. Much less intuitiv

This actually makes sense, since the CNAME does not only replace A records, but any record. Not just MX but your NS and SOA records as well. Much less intuitive is the fact that a MX record cannot refer to a record that is a CNAME itself. http://www.exchangepedia.com/blog/2006/12/should-mx-record-point-to-cname-records.html http://www.exchangepedia.com/blog/2006/12/should-mx-record-p... Many soho routers performing DNS forwarding give very weird and unpredictive results if you do this.