Outgoing SMTP Email Service for Mail Server Administrators

AuthSMTP provides an outgoing SMTP email relay server or 'smart host' for your mail servers with support for all major mail server applications and mail transfer agents. AuthSMTP has many advantages over using your own SMTP server or your ISPs SMTP server such as increased deliverability and less risk of being blacklisted.

Service Features

High performance SMTP gateway with support for multiple concurrent connections for fast delivery.

Some ISPs offer an SMTP service but your mail can be delayed for hours if they get over-loaded / blocked - with AuthSMTP we attempt immediate delivery.

Correct DNS / Reverse DNS / Feedback Loops

All our servers have valid/ correct DNS and reverse DNS entries. We are already signed up with many of the major ISP feedback loops so you receive notification of complaints / improved deliverability

Support for all the major mail server operating systems and software such as:

  • Microsoft Windows Server + Exchange
  • Unix / Linux (Sendmail, Postfix, Exim)
  • IBM Lotus Domino
  • ...and many more.

Automatic virus scanning against all messages

This helps prevent the potentially dangerous / embarrassing situation where someone inadvertently sends or forwards a virus infected email.

Quick and easy to setup guides for most software

We provide clear and easy to follow setup guides for many of the major email server applications and sample configurations for Unix /Linux based programs.

Outgoing email duplication

AuthSMTP can optionally duplicate all the emails you send to an email address of your choice for backup purposes.

Online Control Panel

Control Panel so that you can manage your account online including upgrades, renewal, error logging, address validation and many more features.

Key Benefits

  • SMTP relay / gateway for your network or mail server.
  • Outbound virus scanning & optional email duplication.
  • Support for most major email server applications and mail transfer agents.
  • Full setup guides for most major programs and devices.

Money Back Guarantee

We offer a money back guarantee for your peace of mind so you can sign up and test with no risk. [ Read More ]


Accounts start at a very low cost per year - please see our pricing page for details.

Sign Up

If you have all the information you need and want to sign up for an AuthSMTP account please go to our sign up page. [ Sign Up ]

More Information

If you require more information on the service or have specific technical questions please click more. [ Read More ]