Watchguard Network Security Practice Test

Which option is suitable for preventing mail relay for a specific domain?

1. Rewrite the Mail From header for the example.com domain.

2. Deny incoming mail from the example.com domain.

3. Prevent mail relay for the example.com domain.

4. Deny outgoing mail from the example.com domain.

The correct answer is: Prevent mail relay for the example.com domain.

To effectively prevent mail relay for a specific domain, focusing on a targeted approach is essential. The option that involves directly preventing mail relay for the example.com domain is justified because it addresses the core issue of unauthorized access and the misuse of your mail server to send emails impersonating that domain. Mail relay occurs when an email server allows third parties to send emails while masquerading as a legitimate sender. By explicitly configuring your mail server to prevent relay for a specified domain, you create a security measure that ensures only legitimate emails from that domain can be processed. This proactive configuration keeps your mail server from being exploited for spam or malicious activities. The other options may address different aspects of email management, but they do not specifically solve the relay issue as directly or effectively. For instance, rewriting the Mail From header changes how the email is presented but does not prevent relaying itself. Denying incoming mail blocks legitimate communications from that domain, which could hinder necessary business operations. Similarly, denying outgoing mail affects communications initiated from your server, limiting functionality without solving the relay vulnerability. Thus, the most appropriate and effective choice is directly preventing mail relay for the domain in question.