RMON performs an SMTP check by connecting to the mail server using the credentials specified in the "Username" and "Password" fields. This check is crucial for ensuring the reliability and availability of email services. When attempting to establish a connection, RMON sends a request to the server. If the connection cannot be established within a specified timeout period, RMON sends a warning message.

Additionally, you have the option to check the Ignore TLS/SSL errors box. This feature allows you to avoid receiving alerts about security issues and minor certificate problems.

The check can be created for several countries, regions, or agents at once. To do this, select the desired category in the "Place" field and click + next to the countries/regions/agents for which you want to add the check.

Fill in all the necessary fields, including the "Retries" field, which specifies the maximum number of attempts the system will make to reach the service before it is marked as down and a notification is sent. Additionally, you can specify the runbook in the "Runbook" field to provide a reference guide or set of instructions for troubleshooting the service in case it goes down.

RMON also allows users to configure notifications for alerts about any issues related to SMTP checks by selecting from various channels, including Telegram, Slack, PagerDuty, and/or Mattermost, when adding a new check.