Email MX Records
If you're unsure how to setup your DNS so the email gets directed correctly:
RFC 5321 sec. states that...
- SMTP clients must look up for an MX record;
if no MX record for domain is present, look up for an A Resource Record (RR), and if such record is present, treat it as an MX record;
if an MX record is present, clients MUST NOT use an A RR.