The Best Ways to Do Market Research For Your Business Plan.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks.

First, solve the problem. Then write the code.

Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lo rem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

A programming language is for thinking about programs, not for expressing programs you’ve already thought of. It should be a pencil, not a pen.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Quis ipsum suspendisse ultrices gravida. Risus commodo .

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lo rem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

The Easiest Way to Become a Successful Writer and Authors.

Ressources

Pourquoi devons-nous ajouter nos IPs dans le SPF du client pour utiliser son SMTP ?

Rédigé par Abdelbar SAJI

Comprendre les bases : SMTP et SPF

Un petit rappel

Qu’est-ce que le SMTP ?

Le SMTP (Simple Mail Transfer Protocol) est le protocole standard utilisé pour l’envoi d’emails sur Internet. C’est comme le facteur du monde numérique : il assure la livraison de vos emails à leurs destinataires.

Qu’est-ce que le SPF ?

Le SPF (Sender Policy Framework) est un système de sécurité qui définit quels serveurs sont autorisés à envoyer des emails pour un domaine donné. C’est comme une liste d’expéditeurs de confiance.

Fin du rappel

Mais alors, pourquoi avons-nous besoin d’ajouter nos IPs dans le SPF pour s’authentifier auprès du SMTP ?

C’est là que ça devient intéressant. Même si nous avons les identifiants SMTP corrects, les serveurs de messagerie modernes effectuent une double vérification…

1. Processus d’Authentification SMTP

A. Première Vérification – SPF (La pré-authentification SPF)

• Le serveur SMTP vérifie d’abord l’IP qui tente de se connecter
• Il consulte l’enregistrement SPF du domaine d’envoi
• Si l’IP n’est pas autorisée → rejet immédiat
• Si l’IP est autorisée → passage à l’étape suivante

B. Deuxième Vérification – Identifiants

• Vérification du login/mot de passe
• Cette étape n’est atteinte que si l’IP est autorisée

Sources

La pré-authentification SPF

Le mécanisme de pré-authentification SPF est expliqué dans la section “2.4. Checking Authorization” du RFC 4408 où il est détaillé que :

• Le serveur SMTP effectue d’abord une vérification de l’IP via SPF avant toute tentative d’authentification par login/mot de passe
• Cette double vérification est implémentée comme mesure de sécurité
• Elle forme une première barrière avant même de tenter la vérification des identifiants SMTP

RFC 4408 Section 2.4

À propos du RFC 4408

Le RFC 4408 est un document technique fondamental publié en 2006 par l’Internet Engineering Task Force (IETF). Il a été co-écrit par Meng Weng Wong, l’inventeur du protocole SPF.

Ce document est particulièrement important car :

• C’est la référence officielle qui standardise le protocole SPF
• Il fait partie des RFC (Request For Comments), qui sont les documents techniques définissant les standards d’Internet
• Il est largement adopté par l’industrie du mail
• Il reste aujourd’hui la base des implémentations SPF actuelles

2. Exemple Technique Détaillé

Scénario :

Dans cet exemple, notre serveur 4D ne fait qu’une demande d’envoi au SMTP d’OVH. Ce n’est pas le serveur 4D qui envoie directement le mail, mais bien le serveur SMTP d’OVH qui s’en charge.

• Le serveur 4D (IP: 82.45.128.10) demande au SMTP d’OVH d’envoyer un email
• Cette demande passe par le serveur smtp.ovh.net
• Pour l’adresse email exemple@client.com

Le SPF du domaine est le suivant :

v=spf1 include:mx.ovh.com ~all

Voilà ce qui se passe au niveau du serveur SMTP d’OVH :

Tentative de connexion depuis 82.45.128.10
Vérification SPF de client.com
IP non listée dans : v=spf1 include:mx.ovh.com ~all
→ Authentication failed (rejet immédiat)

Le nouvel enregistrement devient :

v=spf1 include:mx.ovh.com ip4:82.45.128.10 ~all

Avec ce nouvel enregistrement, voilà le retour :

Tentative de connexion depuis 82.45.128.10
Vérification SPF de client.com
IP listée dans : v=spf1 include:mx.ovh.com ip4:82.45.128.10 ~all
→ Vérification des identifiants SMTP
→ Authentication successful

3. Pourquoi Cette Sécurité ?

Protection contre :

• L’usurpation d’identité par email
• Les tentatives de brute force des mots de passe SMTP
• L’utilisation non autorisée des serveurs SMTP

The Quickest Way to Deliver Your Message? Make It Visual.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks.

First, solve the problem. Then write the code.

Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lo rem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

A programming language is for thinking about programs, not for expressing programs you’ve already thought of. It should be a pencil, not a pen.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Quis ipsum suspendisse ultrices gravida. Risus commodo .

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don’t look even slightly believable. If you are going to use a passage of Lorem Ipsum. You need to be sure there isn’t anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend toitrrepeat predefined chunks. Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.

Necessary, making this the first true generator on the Internet. It re are many variations of passages of Lo rem Ipsum available, but the majority have suffered alteration in some form, by injectedeed eedhumour, or randomised words which don’t look even slightly believable.