February 2024
Beginner to intermediate
304 pages
9h 13m
Japanese
Content preview from 実務で使える メール技術の教科書 基本のしくみからプロトコル・サーバー構築・送信ドメイン認証・添付ファイル・暗号化・セキュリティ対策まで
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Let'slearnaboutemailtechnology!
■ From 欄の偽装
第 2 章で解説したように、メールの本文にある From 欄は自由に記述でき
るため、差出人の名前は容易に偽装できます。つまり、他人になりすまして
メールを送信することは難しくありません。
SMTPのプロトコルを Telnetで入力する方法だけでなく、メールソフトを
使って偽装する方法もあります。Gmail の設定画面で送信者の名前を入力する
欄に適当な名前を入れて、自分宛に送信してみましょう【図 5-1】。
図 5-1
Gmail における送信者名の設定
適当な名前を入れる
5
1
差出人の偽装による攻撃
・差出人の偽装を警戒したい方
・大量のエラーメールによるスパムメールのしくみを知りたい方
使えるのはこんな人や場面！
186
185-216̲mail̲NSM̲F3.indd186185-216̲mail̲NSM̲F3.indd186 2024/01/309:532024/01/309:53
5
1
差出人の偽装による攻撃
この画面で名前を変更すると、メールアドレスはそのままですが、相手に届
いたときにメールの差出人の名前の欄には、書き換えた値が表示されます。
普段からメールアドレスを見ることなく、 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.