This information is only valid for mail domains redirected to third party mail providers.
A mail exchanger record specifies the mail server responsible for accepting email messages on behalf of a domain name. It is a resource record in the Domain Name System. It is possible to configure several MX records, typically pointing to an array of mail servers for load balancing and redundancy.
Obtain a list of MS records from your mail service provider and repeat the following steps for each MX record:
Because of DNS replication delay the new MX record may not be available for some time (1 -2 hours).