Which environment involves deleting email mailboxes at the Defense Enterprise Email System?

The correct choice pertains to the garrison environment, which is characterized by a more stable and permanent setup compared to others. In garrison environments, management tasks such as deleting email mailboxes in the Defense Enterprise Email System are conducted regularly as part of administrative duties. This includes maintaining user accounts, managing resources, and enforcing security policies, all of which are essential in supporting the operational readiness of the organization.

The distinction of the garrison environment comes from its structure, where personnel are more frequently stationed in a fixed location, allowing for systematic management of resources, including email services. Other environments, such as tactical or field environments, may focus on immediate operational needs and response capabilities, which typically wouldn't prioritize routine mailbox deletions as part of their operational focus. The remote access environment is also dedicated to allowing users to connect to resources from outside their typical work environment, often emphasizing security and accessibility over mailbox management. Therefore, the process of deleting email mailboxes aligns with the defined operational procedures in a garrison setting, making it the correct answer.