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's learn about email technology!
■ DMARC の設定
このように、SPF や DKIM といった送信ドメイン認証の技術が用意され、
一定の効果はあるものの、第三者がなりすましてこれを避けることもできてし
まうことについて解説しました。
また、SPF や DKIM は受信側のメールサーバーが送信元を認証するための
しくみであり、第三者によってなりすましたメールが勝手に送信されていても、
送信側は何も検知できません。所有しているドメインを使って悪意のあるメー
ルが大量送信されていても、異なるメールサーバーから送信されていると、気
づくことは困難です。
そこで、DNS サーバーに設定した SPF や DKIM の情報に加え、ヘッダー
の From の情報を組み合わせて送信ドメイン認証を実現する技術として
DMARC（Domain-based Message Authentication, Reporting and
Conformance）があります。
名前に「Reporting」という言葉が入っているように、認証の結果を報告し
てくれるしくみが含まれていることが特徴です。
また、SPFでは、エンベロープFromを基準に確認していましたが、
DMARC はヘッダーの From も使って確認することが特徴です。つまり、
SPF であればヘッダーの From とエンベロープ From、HELO の IP アドレス
を検証します。
さらに DMARC では、SPF や DKIM ...
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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.