How to configure a Relay Server in IceWarp

The relay server can be configured through the Administration Console under Mail > General.

There are two ways the relay server can be used:

1. Primary Relay – All outgoing emails are sent through the relay server.
2. Fallback Relay – Enabled via "Deliver messages via relay server when direct delivery fails" checkbox. Emails will only be sent through the relay server if delivery through IceWarp's SMTP fails.

The setup process is the same for both options. You must enter the necessary details in the Use Relay Server field.

The Use Relay Server field must be filled out using one of the following formats:

• <username>:<password>@<relay_hostname>
• <username@domain.com>:<password>@<relay_hostname>

You can also specify a custom port by adding it to the hostname, using the following format:

• <username@domain.com>:<password>@<relay_hostname:port>

Note: The default port is 25. If port 25 is blocked or you prefer to use a different port (e.g., for SSL/TLS), you must specify it explicitly.

Example with a custom port:

email@domain.com:SecurePassword123*@mail.relay.com:465