When information devices use the 【email】 method to send messages to a designated email mailbox, they can be filtered and compared by the Watchdog system or directly treated as alert events, and handled according to the alert mechanism.



There are two types of usage for the 【Email Forwarding Mechanism】:
➢ Local Mailbox:
Use the Watchdog host as the SMTP email server to receive and process alert messages from various information devices.
Especially when these devices send alerts via email, Watchdog can act as the SMTP server to receive and handle these alert emails.
On the Watchdog host, a dedicated program using TCP port 25 to receive email SMTP is already configured,
so users do not need additional SMTP server configurations.
The email forwarding function allows the Watchdog system to serve as a centralized alert management point, receiving, analyzing, and processing alerts from different information devices, achieving automated and centralized alert management.

➢ Remote Mailbox:
Use another host as the SMTP email server and retrieve emails regularly via the POP3 protocol.
This function is another application of the Watchdog system in email forwarding. The main working method is similar to 【Email Forwarding - Local】, but the core difference lies in the choice of the SMTP server.

➥ Application of External SMTP Server: Unlike using the Watchdog host directly as the SMTP server, this function allows the use of an external host as the SMTP server. This means that the emails are not sent directly to the Watchdog host but first sent to the external host, and then retrieved by the Watchdog host through a specific protocol.

➥ Application of POP Protocol: The Watchdog system communicates with the external SMTP server via the Post Office Protocol (POP) and retrieves the emails stored on that server. This process involves authentication, so it requires configuring the corresponding username and password on the Watchdog host.

➥ Triggering the Alert Mechanism: Once the Watchdog successfully retrieves the emails via the POP protocol, it will directly issue an alert notification.

Two Alert Handling Conditions:
When the Watchdog system receives the email, it can perform subsequent processing actions for the email.
➢ Directly compare the message content via alert conditions. If it matches the conditions, it is considered an alert event and handled according to the alert mechanism.
➢ Directly consider the message content (email subject) as an alert event and handle it according to the alert mechanism.

For a more comprehensive understanding and practical application of 【Email Forwarding】,
please explore more detailed information through the 【Email Forwarding - Detailed Function Description】 link.