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
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.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.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.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.
Let's learn about email technology!
■ ブラックリストと IP レピュテーション
送信者のメールアドレスや本文の内容をチェックするのではなく、特定の
メールサーバーから送信されるメールを拒否したい場合もあります。あるメー
ルサーバーが乗っ取られて、そこから大量のメールが送信されている、といっ
た場合です。このようなメールサーバーからのメールは一律で拒否したいもの
です。
そこで、大量にスパムメールを送信しているようなメールサーバーの IP ア
ドレスをリストとして登録しておき、そのリストに含まれるメールサーバーか
らのメールを拒否する方法が考えられます。このような IP アドレスのリスト
をブラックリストといいます【図 5-18】。
送信したメールの量が大量でなくても、利用者からの迷惑メール報告数が多
い場合は、それがブラックリストに登録される可能性もあります。Gmail のよ
うなサービスでは、多くの利用者がおり、迷惑メールとして報告する機能があ
るため、その量が増えると迷惑メールとして扱われる可能性が増えます。
図 5-18
ブラックリストのしくみ
通常の配信者
スパム配信者
スパム配信者
234.32.109.87
201.234.56.78
210.98.76.54
ブラックリスト
・210.98.76.54
・201.234.56.78
・…
220
217-228̲mail̲NSM̲F2.indd220217-228̲mail̲NSM̲F2.indd220 2024/01/2510:09 ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.