Exim is a full-featured, high-performance mail transfer agent (MTA) used primarily for Unix-like systems. It is a production-quality server that is used to receive, route and deliver emails. Exim is highly configurable and provides features such as mailing list management, filtering and support for both SMTP and POP3 protocols.
The prerequisites for monitoring Exim with Netdata are to have Exim and Netdata installed on your system.
Netdata auto discovers hundreds of services, and for those it doesn’t turning on manual discovery is a one line configuration. For more information on configuring Netdata for Exim monitoring please read the collector documentation.
You should now see the Exim section on the Overview tab in Netdata Cloud already populated with charts about all the metrics you care about.
Netdata has a public demo space (no login required) where you can explore different monitoring use-cases and get a feel for Netdata.
The number of emails waiting to be sent from the Exim mail transfer agent (MTA). This metric is important to monitor because if too many emails are queued up, it can lead to email delivery delays or even email delivery failure. It is also important to monitor this metric to ensure that malicious actors are not attempting to send large volumes of emails in an attempt to overwhelm the system. Generally, a healthy system should have a low number of emails in the queue. Depending on the system, normal values range from 0 to a few hundred.