DMARCエラーの修正：Fromヘッダーと一致するようにReturn-PathまたはDKIMをアラインメントさせる
SPFやDKIMが正常にパスしていても、Return-PathまたはDKIM署名ドメインが表示上のFromアドレスと一致していない場合、DMARCは失敗することがあります。生のヘッダーから不一致を特定し、修正する方法を学びましょう。
GyaanSetu WebDev
Frontend, backend and devops for the modern web.
MCPサーバーに人間による承認ゲートを実装、AIによる金融データの削除を防止
AI家計簿エージェントをMCPサーバー経由で動作させた際、わずか一回のコマンドで1年分の取引履歴が消去されかねない事態が発生しました。しかし、ツールレイヤーにハードコードされたセーフティチェックがこの削除を阻止しました。この事例は、安全策の強制はプロンプトではなく、API側で行うべきであることを証明しています。
Three hundred and thirty humans served daily. The electricity bill comes to forty two dollars per year. That is not a ro
Three hundred and thirty humans served daily. The electricity bill comes to forty two dollars per year. That is not a rounding error or a gimmick. It is the actual operating cost…
If you have ever tried to pull bold or italic text out of a PDF, you probably started with a regex. It feels like the ob
If you have ever tried to pull bold or italic text out of a PDF, you probably started with a regex. It feels like the obvious move. Search the font name for the word “Bold,” flag…
どの開発者にも、あのフォルダがあるはずだ。リポジトリからリポジトリへと使い回す、あのフォルダ。それを貼り付けて、20分間...
どの開発者にも、あのフォルダがあるはずだ。リポジトリからリポジトリへと使い回す、あのフォルダ。それを貼り付けては、古いデータベーススキーマへの参照を削除したり、不要な部分を削ぎ落としたりするのに20分も費やすことになる……
Developers often ask me the same question: "My API is slow. Where do I start?" The reflex is usually to upgrade the serv
Developers often ask me the same question: "My API is slow. Where do I start?" The reflex is usually to upgrade the server or double the RAM. That costs money and rarely fixes the…
大規模言語モデルをスマートフォン上で動作させることは、もはや研究段階の実験ではなく、製品化が現実のものとなっています。しかし、その...
大規模言語モデルをスマートフォン上で動作させることは、もはや研究段階の実験ではなく、製品化が現実のものとなっています。しかし、単なるデモから実際の製品へと移行した途端、レイテンシが……
多くのプログラマーには盲点があります。分散システムのデバッグや新しいフレームワークとの格闘は喜んで行うのに、それでも...
多くのプログラマーには盲点があります。分散システムのデバッグや新しいフレームワークとの格闘は喜んで行う一方で、結局、数分間の手作業によるテキスト編集に20分も費やしてしまったりするのです…。
私のMCPサーバーが、ただ突然動かなくなることがありました。クラッシュダンプも、ログにスタックトレースもありません。クライアントは問題なく接続していました。
私のMCPサーバーが、ただ突然動かなくなることがありました。クラッシュダンプも、ログにスタックトレースもありません。クライアントは問題なく接続していましたが、数時間後にはすべてが反応しなくなってしまいました。リクエストが…
I started with a notebook. Not a text editor or a markdown file, but a spiral bound paper notebook filled with commands
I started with a notebook. Not a text editor or a markdown file, but a spiral bound paper notebook filled with commands I did not understand. I wrote down , , , , and . I stacked…
Most frontend code treats asynchronous work like a single shape. You kick off a Promise, wait for it to resolve, dump th
Most frontend code treats asynchronous work like a single shape. You kick off a Promise, wait for it to resolve, dump the result into local state, and let the framework reconcile…
Building a directory site sounds trivial until you find yourself wiring up databases, caching layers, and reactive front
Building a directory site sounds trivial until you find yourself wiring up databases, caching layers, and reactive front end frameworks just to display what is essentially a curat…
People have grown tired of treating romance like a slot machine. Open a dating app. Swipe. Swipe. Swipe. The mechanic th
People have grown tired of treating romance like a slot machine. Open a dating app. Swipe. Swipe. Swipe. The mechanic that once felt efficient now feels hollow. Most platforms sti…
アップタイムダッシュボードは嘘をついています。サイトはオンラインで、ホームページも読み込まれ、SSL証明書も有効だと表示されています。Ev
アップタイムダッシュボードは嘘をついています。サイトはオンラインで、ホームページも読み込まれ、SSL証明書も有効。すべてのピクセルが本来あるべき場所に正しく表示されている。しかしその一方で、あなたの…
Angular forms work beautifully with standard HTML. , , and all slot into Reactive Forms without extra effort. The framew
Angular forms work beautifully with standard HTML. , , and all slot into Reactive Forms without extra effort. The framework understands their events, their values, and their state…
Every web developer knows the feeling of watching their application render perfectly in a controlled staging environment
Every web developer knows the feeling of watching their application render perfectly in a controlled staging environment. Shipping an embedded widget destroys that comfort entirel…
If you have ever refreshed a page and watched your CSS vanish, or reverted a file only to realize you cannot remember wh
If you have ever refreshed a page and watched your CSS vanish, or reverted a file only to realize you cannot remember what you changed, you understand the gap between writing code…
One line of code can undo your entire access control model. Spread the request body straight into a database update and
One line of code can undo your entire access control model. Spread the request body straight into a database update and you have handed the client a pen to rewrite your schema. Th…
You optimized the endpoint. Your resend email API responds in under half a second. And yet users still open support tick
You optimized the endpoint. Your resend email API responds in under half a second. And yet users still open support tickets saying the link never arrived. They click twice. They a…
When someone tells you they shipped 335 live pages across 26 repositories in 29 days, working alone, the instinct is to
When someone tells you they shipped 335 live pages across 26 repositories in 29 days, working alone, the instinct is to ask how they moved so fast. The better question is what bro…
If your email tests run perfectly on your laptop and collapse the moment they hit CI, you are not alone. The usual respo
If your email tests run perfectly on your laptop and collapse the moment they hit CI, you are not alone. The usual response is to sprinkle calls through the test code or bump the…
Every engineering team wants a system that grows without groaning. We picture traffic climbing smoothly, servers humming
Every engineering team wants a system that grows without groaning. We picture traffic climbing smoothly, servers humming, and revenue ticking upward. Then reality hits. A viral ma…
For weeks, a cron job at Elevare Digital woke up on schedule, checked its queue, and logged a clean success. It approved
For weeks, a cron job at Elevare Digital woke up on schedule, checked its queue, and logged a clean success. It approved exactly zero drafts. Nineteen pieces of content sat waitin…
Every piece of software you use today was built around a single assumption. Someone with fingers is sitting in front of
Every piece of software you use today was built around a single assumption. Someone with fingers is sitting in front of a screen. Buttons imply intent. Wizards manage complexity.…