問85
頻出度★★☆
電子メールに関する説明のうち, 適切なものはどれか。
平成28年度 秋期 ITパスポート試験 問85
テクノロジ系ネットワーク › 通信プロトコル
This question's explanation and your answers so far.
解説
問 85
- ア
正解 Option ア is correct. IMAP4 (Internet Message Access Protocol version 4) is a receiving protocol that keeps received e-mail on the mail server for viewing and management. Because the message body, read/unread status, folder structure, and so on are held on the server side, even when you access the same mail account from multiple devices such as a PC and a smartphone, you can handle the mail in the same state on any device. Therefore, the statement that it is “convenient when using a single mail account on multiple devices” correctly describes the characteristics of IMAP4 and is appropriate.
Incorrectイ
MIME (Multipurpose Internet Mail Extensions) is not a “receiving protocol.” MIME is an extension mechanism that lets e-mail — which originally could handle only text — also handle non-text data such as images, attachments, and various character encodings. The protocols for receiving e-mail are POP3 and IMAP4, so this option confuses their roles and is incorrect.
Incorrectウ
POP3 (Post Office Protocol version 3) is not a protocol for “sending” but for “receiving.” It is used to download and receive e-mail from the mail server to a specific device. The protocol used to send e-mail is SMTP, so describing POP3 as a sending protocol is incorrect.
Incorrectエ
SMTP (Simple Mail Transfer Protocol) is a protocol for “sending and relaying” e-mail. The mechanism that enables e-mail to handle data formats other than text is the role of MIME, so this description of SMTP is incorrect.
ここがポイント
- Distinguishing the roles of e-mail-related protocols: SMTP = sending, POP3 = receiving (downloaded to a device for management), IMAP4 = receiving (mail managed on the server), MIME = a format-extension mechanism for handling non-text data.
- The difference between IMAP4 and POP3: because IMAP4 keeps and manages mail on the server, the same account can be viewed in the same state from multiple devices such as a PC and a smartphone, making it suitable for multi-device use.
用語