Email Probe Configuration in Proberix

This guide explains how to set up and configure Email probes in Proberix to monitor the availability of email servers via common protocols like SMTP, IMAP, and POP3. These probes help ensure your email infrastructure is reachable and properly responding to protocol handshakes.

Required Configuration

The following fields are mandatory when configuring an Email probe:

Host/IP:
The address of your email server (e.g., mail.example.com). Local/private addresses are not supported.

Port:
The port number your service is listening on:

• SMTP: typically 25, 465, or 587
• IMAP: usually 143 or 993
• POP3: typically 110 or 995

Protocol:
One of the supported email protocols:

• SMTP
• IMAP
• POP

Optional Configuration

Use Secure Connection:
When enabled, the probe uses a secure TLS connection to communicate with the email server. This is commonly required for encrypted ports such as 465 (SMTP), 993 (IMAP), or 995 (POP3).

Reject Unauthorized:
When enabled, the probe verifies the server’s TLS certificate. If disabled, self-signed or invalid certificates are tolerated. Use with caution.

Monitoring Process

Email probes in Proberix follow protocol-specific workflows:

1. Connect to the specified host and port (with or without TLS).
2. Read the initial greeting from the server.
3. Issue a basic protocol command:
   • SMTP: expect a 220 greeting, then send QUIT
   • IMAP: expect an OK greeting, send CAPABILITY, wait for A1 OK
   • POP3: expect a +OK greeting, then send QUIT
4. Validate the response format to confirm the server is behaving correctly.

Status Outcomes

• "ok" — Server responded with the expected greeting and accepted commands
• "unreachable" — Server did not respond or failed to accept the connection
• "error" — Protocol violation, TLS handshake failure, or malformed response

Best Practices

• Choose the correct port/protocol pair for your infrastructure (e.g., IMAP + port 993 with TLS).
• Enable TLS with strict verification for production services to ensure secure monitoring.
• Regularly monitor your MX and email server availability alongside DNS and TCP probes for comprehensive visibility.
• Use Email probes for real-time feedback on SMTP gateway reachability and spam filtering outages.

Advanced Considerations

Email probes in Proberix are designed for connection-level verification only. They do not authenticate with credentials or send/receive actual email content. This makes them safe for frequent uptime checks without altering inbox state or triggering mail delivery.