Can I Run an Email Server Using a Free No-IP Hostname?

Yes, but most ISPs (Internet Service Providers) block port 25 (mail port) for both inbound and outbound. You will need No-IP Reflector to help you get around your ISP for inbound email and No-IP Alternate-port SMTP can help with outbound email.

If you’d like to use your free hostname with a mail service, you should be able to create up to 5 MX records under any No-IP hostname. In order to do this please navigate the left side menu to Dynamic DNSNo-IP Hostnames > Modify on the desired hostname. At the bottom of the modification page, you will see the section to enter the required MX records. From here you should be able to enter the hostname of your email server in the external mail exchanger field (MX Record) when modifying the host that you wish to accept mail.