To have your email hosted at Greatmail, point your domain’s MX record to:
smtp.greatmail.com
In a DNS manager, there are several parameters for the MX record:
Host or Name: The domain name for the MX record.
Class: IN for Internet.
Type: MX for Mail Exchanger.
TTL: “Time to Live” specifies how long the record will take to update in seconds. For example, a TTL of 3600 seconds will take one hour to update.
Preference or Priority: For domains with multiple MX records, the lowest number entry is the highest priority or preference.
Data, Value or Points To: The name of the mail server that handles mail for this domain.
The following MX record in a zone file:
yourdomain.com. IN MX 10 smtp.greatmail.com.
specifies ‘smtp.greatmail.com’ to receive mail for ‘yourdomain.com’.