2.2.11 [RFC1939] Section 8, Scaling and Operational Considerations

E0003:

The specification states: "Imposing a per-user maildrop storage quota or the like."

Microsoft Exchange Server 2007, Microsoft Exchange Server 2010, Microsoft Exchange Server 2013, Microsoft Exchange Server 2016, Microsoft Exchange Server 2019

Microsoft Exchange Server mailboxes can be configured to have a storage quota. Each user mailbox has a storage quota that is inherited from the storage database configuration. Storage quotas for each mailbox can be changed using the Exchange Management tools.

E0004:

The specification states: "Sites which choose this option should be sure to inform users of impending or current exhaustion of quota, perhaps by inserting an appropriate message into the user's maildrop."

Exchange 2007, Exchange 2010, Exchange 2013, Exchange 2016, Exchange 2019

Exchange management tools can be used to configure on a per-mailbox basis to warn users that are near their maximum mailbox size.

E0005:

The specification states: "Sites are free to establish local policy regarding the storage and retention of messages on the server, both read and unread. For example, a site might delete unread messages from the server after 60 days and delete read messages after 7 days."

Exchange 2007, Exchange 2010, Exchange 2013, Exchange 2016, Exchange 2019

Microsoft Exchange supports a limited retention policy that can be configured to auto-delete mailbox items based on age. However, this feature is exposed as part of the Exchange storage facility and is not a POP3-specific feature.