POP has two modes: the Delete mode and the Keep mode.
In the Delete mode - The mail is deleted from the mailbox after each retrieval.The delete mode is normally used when the user is working at her permanent computer and can save and organize the received mail after reading or replying.
In the Keep mode – The mail remains in the mailbox after retrieval.The keep mode is normally used when the user accesses her mail away from her primary computer (e.g., a laptop).The mail is read but kept in the system for later retrieval and organizing.
Thus, only (a),(b),(e) statements are correct.Option (D) is correct answer.