No, MX records must not point to an IP address. MX records should point to address records (A or AAAA), domains, or hostnames.
Category: DNS
Can I point an MX record to a CNAME record?
No, MX records must not point to CNAME records. In the following example, the specified MX record for greatmail.com is invalid because it points to a CNAME : greatmail.com.com MX mail.greatmail.com mail.greatmail.com CNAME mail2.greatmail.com An MX record must point to an address record (A or AAAA). The following MX and A records are correct: greatmail.com.com MX mail.greatmail.com mail.greatmail.com. IN A 208.70.245.70