Which action does whitelisting an email domain in Zendesk allow?

Whitelisting an email domain in Zendesk permits emails from that specific domain while blocking all others. This action is crucial for ensuring that messages from trusted sources, such as partners, customers, or other relevant stakeholders, are consistently received without being filtered out as potential spam or undesired communications. Whitelisting effectively creates a safe list, ensuring that important communications from these domains are prioritized and not hindered by the platform's security measures.

This action is particularly useful in scenarios where a business wants to maintain open lines of communication with key contacts, ensuring that their messages are allowed through the system without interference. Such functionality is integral for maintaining effective customer support and ensuring vital information is not missed or delayed.

While other options might seem plausible at first glance, they do not accurately reflect the functionality of whitelisting within Zendesk's email handling system.