An MX record (Mail eXchanger) tells senders how to send email for your domain.
When you register your domain, it is assigned several DNS (Domain Name System) records. These records enable your domain to be located on the Internet. One such record is the MX record, which directs the domain’s inbound mail flow ie. the MX record defines how inbound email will be routed for your domain. These MX records are read by mail servers to determine where to send messages to.
For users to send and receive email, their domain's MX records must point to a server that can process their mail.
If your organization receives email directly, then your MX record would typically point to a public IP address for your firewall or Email server, normally entering via SMTP port 25.
Your authoritative MX records are on your DNS provider's Internet server. When you change the MX record on your DNS provider to point to MailShark, other servers will make copies of these updated MX records over time. This is normally done on the web interface of your domain registrar.
The above diagram illustrates how mail will flow once your MX records point to MailShark.
If you have difficulty or need assistance with configuring your MX record, simply raise a Help desk request at MailShark Support.