How to Create Devices and Targets

How it Works

During SMTP monitoring, the agents monitor the SMTP server by connecting to the specified mail server and performing an SMTP handshake. If a remote server does not respond to a handshake or is unavailable, an error condition will be triggered.  If you have alerts configured, you will receive an alert.

Creating a Target

Hostname / Port

Enter the SMTP server address and port number. This could be the URL or the IP address.

Time Validation Threshold (in seconds)

This setting specifies the maximum time, in seconds, that the system will wait for a response from the target resource. If the response is not received within the defined time, the system flags it as an error.

Encryption

When enabled – SMTP over SSL/TLS will be requested:

  • YES explicit – connects to the server and explicitly requests TLS encryption to be enabled by sending the STARTTLS command to the server. Default port is Port 587.
  • YES implicit – TLS encryption is switched on implicitly for receiving mail over an encrypted connection. Default port is Port 465.
  • None – ncryption is not used. Username/password can be sent encrypted (e.g., by using base64). Default port is Port 25.
  • Auto – TLS encryption will only be used if Dotcom-Monitor client considers it necessary and if the server informs the client that it supports TLS encryption.

If you select encrypted connection, please make sure there is the correct port number in the Hostname / Port fields. If the port number is not specified, a default port will be used instead.

Login to Server

Disabled

When Login to Server is disabled, Dotcom-Monitor connects to the specified SMTP server and port and verifies that the connection is successfully established.

Enabled
When Login to Server is enabled, Dotcom-Monitor performs SMTP authentication using the credentials provided in the Login Information section:

  • User Name: Username used for SMTP authentication.
  • Password: Password used for SMTP authentication.

The monitor attempts authentication using the following mechanisms:

  • CRAM-MD5
  • LOGIN
  • PLAIN
  • SIMPLE
  • SSL/TLS

Authentication is initially attempted over an unencrypted connection. If all authentication methods fail, Dotcom-Monitor® upgrades the connection to SSL/TLS and retries each supported authentication mechanism until a successful response is received, in accordance with RFC 5034 authentication framework guidelines.

The monitor reports a successful result as soon as any authentication method succeeds. If all authentication attempts fail, the monitor reports an authentication error.

Modern Authentication (OAuth 2.0)

If the SMTP server requires Modern Authentication, configure OAuth 2.0 authentication instead of Basic Authentication. For Exchange Online (Microsoft 365), follow the instructions in Using Modern Authentication for Exchange Online | Office 365 | Microsoft 365 Monitoring to generate the required OAuth 2.0 refresh token and prepare the authentication script before configuring the SMTP monitoring device. Add the authentication script to the Prepare Script field under the Scripts tab.

Scripts

The fields can contain C# code, which can be used for specific POST, GET, URL data or for validating or publishing custom headers. Please see the Using Prepare Script and Post Script article or contact technical support for more details on usage.

DNS Options

The DNS Options feature allows users to choose how domain name server (DNS) requests are conducted during a monitoring task.

To specify the mode of resolving hostnames, in the DNS Resolve Mode section, select one of the available modes. For more details on the feature configuration, see DNS Mode Options.

The Custom DNS Hosts section allows to set up the mapping of IP addresses to hostnames. IPv6 and IPv4 DNS resolution is supported.

To specify the mapping, enter the IP address and the hostname in the corresponding fields.

Examples:

192.168.107.246   example.com user.example.com userauth.example.com tools.example.com
192.168.107.246   example.com
192.168.107.246   user.example.com
192.168.107.246   userauth.example.com

See also: DNS Mode Options.

SMTP servers are allowed only to accept connections from a specific list of hosts. So, in order to proceed with monitoring without obstacles, Dotcom-Monitor monitoring agents should be white-listed in a firewall.