What is a relay server? Do I need one?

A relay server is a mail server (usually SMTP server only) that delivers mail for a 3rd party mail server that is unable to do this on its own due to ISP restrictions, configuration issues and many other factors that may prohibit successful email delivery. Think of a relay server like a package delivery service, you have a package that needs to be sent to a specific location, you cannot do it, so you have this service pick up and take the package, run it through their systems to be placed on a truck for delivery to the final destination. This service is perfect for the following setups or situations…

  • Host your own mail server and your ISP blocks port SMTP port 25
  • Host your own mail server and your IP address is classified as a residential or dynamic IP address
  • Your mail server’s IP address has no reverse DNS configured and your ISP does not allow you to setup reverse DNS
  • You run an Exchange (or any other mail server) and require a “Smart Host” or outbound relay server to send your email
  • Your mail server’s IP address is listed on 1 ore more realtime blacklists (RBL) services and your ISP will not request delisting or you cannot request delisting

Can I send spam or unsolicited email?

No. ASPnix does not allow the sending of spam or unsolicited email of any kind and has a zero-tolerance policy for spreading or sending of spam using our mail relay service.

Service Features

  • Send mail from any IP address, mail server (supporting Smart Hosts or relay authentication) using any domain name that you own!
  • Alternate SMTP ports available to void ISP blocking of the standard SMTP server port. Including 21, 25, 26, 88, 2525, 8080.**
  • 50MB maximum message size (including attachment(s) and the attachment(s) MIME encoding)
  • 1000 recipients maximum per email (limited by the number of relays you purchase)


Relays per day*Monthly PriceAnnual Price

Signup / Register

Risk free sign up! Remember that we offer a 30-day money back guarantee! See our refund policy article for more. If you have any questions regarding our email relay services or if your server supports Smart Hosts or relay / outgoing authentication, do not hesitate to contact one of our skilled and knowledgeable sales team members!

* 1 “relay” is counted for each recipient of a message that is sent. For example, if you sent 1 email to 100 recipients that would be 1 connection per recipient and 1 email in queue per recipient for a total of 100 relays. Relay counters are reset daily.

** Please contact your ISP for information regarding running a mail server on their network. ASPnix takes no responsibility if your ISP suspends or deactivates your internet services due to violations of their TOS.