Icewarp offers a Server diagnostics option, located in System/Services.

It will check for several important factors, as shown below, in an example test, where everything is succesfull.

Testing DNS Server '70.84.161.10;70.84.160.10;ns.lucanet.com.br'...
DNS query test successful.
Testing Primary Domain 'lucanet.com.br' for MX Record...
Primary Domain Test Successful.
Testing Internet Connectivity...
Internet Connectivity Test Successful.
Testing Internet Services...
Internet Services Test Successful.
Testing SMTP Message Transfer...
SMTP Message Transfer Test Successful.

Server Diagnostics Successful.

Note that:

- Your DNS servers, specified in System/Internet connection are tested. Specify several DNS servers separted by semi-colons (;). Be sure to specify DNS servers that let your system/IP do recursive queries, so it can find out the MX of destination servers, where it has to send mail out to.

- It will check if your primary domain has a valid MX record, so it can receive emails from remote systems. The primary domain is the one that appears first, at the top, in the Icewarp console, in Domains & Accounts management. To make a specific domain the primary one, right click on it and choose Make Primary. Note that the email administrator account defined in the primary domain receives important messages, such as system errors and information about licenses whose upgrades are expiring.

- Internet connectivity and services are tested