メールは「ヘッダ」と「本文」によって構成されています。たとえば、次のメールの例では
Return-Path: <nagoya@cc.hit-u.ac.jp> Delivered-To: yy00004@srv.cc.hit-u.ac.jp Received: (qmail 1281 invoked from network); 13 Feb 2001 02:28:01 +0900 Received: from adm.cc.hit-u.ac.jp (133.46.10.99) by srv.cc.hit-u.ac.jp with SMTP; 13 Feb 2001 02:28:01 +0900 Received: (qmail 25119 invoked from network); 13 Feb 2001 02:28:00 +0900 Received: from gemini.cc.hit-u.ac.jp (HELO localhost) (133.46.10.11) by adm.cc.hit-u.ac.jp with SMTP; 13 Feb 2001 02:28:00 +0900 To: yy00004@srv.cc.hit-u.ac.jp Cc: nagoya@cc.hit-u.ac.jp Mime-Version: 1.0 Content-Type: Multipart/Mixed; boundary="--Next_Part(Tue_Feb_13_02:27:41_2001_203)--" Content-Transfer-Encoding: 7bit Message-Id: <20010213022800T.nagoya@cc.hit-u.ac.jp> Date: Tue, 13 Feb 2001 02:28:00 +0900 From: nagoya@cc.hit-u.ac.jp Subject: Hello ----Next_Part(Tue_Feb_13_02:27:41_2001_203)-- Content-Type: Text/Plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit こんにちは、お元気ですか。山の写真を送ります。 ----- nagoya ----Next_Part(Tue_Feb_13_02:27:41_2001_203)-- Content-Type: image/jpeg Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="hotaka1.jpg" /9j/4AAQSkZJRgABAQAAAQABAAD//gB+RmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hv ... AkURjikOAyY7d62IvDkZuPMXIjYZZSuck+mfxq9a6ZZW05liCqc8hT1qblM//9k= ----Next_Part(Tue_Feb_13_02:27:41_2001_203)----