What does the 'we do not relay' error mean?

If you cannot send a message and server's response is 'we do not relay', the problem is probably that you are not authenticated.

Merak Email Server provides three main ways for a user to authenticate.

  1. Relay IPs
  2. POP before SMTP
  3. SMTP Authentication

The first two of these options are in Mail Service -> Security.

Relay IPs

This allows you to directly authenticate any sender who relays from IPs specified in the list.

Security - Anti Relaying Tab - Relay IPs Section

127.0.0.1 should always be there, this is the local IP address of the hosting machine.

The IP of your server and internal LAN IPs should also be there.

Other IP address should be added only if they are to be trusted.

Any sender coming from IP addresses need to authenticate themselves by one of the other methods.

POP before SMTP

Another way of authenticating senders is called POP before SMTP.

When enabled any user who downloads messages via POP3 will be automatically be allowed to send messages through your server for the specified time.

Security -

So in the above example, any user who collects mail via POP3 will be allowed to send mail for 45 minutes.

SMTP Authentication

This is enabled by default and requires a valid User/Password to be used before SMTP sending is allowed.

You should ensure your email client is set to authenticate its SMTP connection.

Note that the recommended method to use is SMTP Authentication. Both the Relay IP and POP before SMTP methods introduce a security risk and should be avoided if possible.

You can use the service at www.abuse.net to check if your server is not Open Relay.