E-mail Spoofing : Comment l’éviter et protéger votre entreprise
Vous est-il déjà arrivé de recevoir un e-mail qui semblait légitime — avec le bon logo, un ton familier — mais qui vous a tout de même paru suspect ? Pire encore, un de vos clients vous a-t-il déjà contacté après avoir reçu un e-mail douteux qui semblait provenir de votre entreprise ?
C’est ça, le spoofing d’e-mail.
Le spoofing d’e-mail est une technique utilisée par des cybercriminels pour falsifier l’adresse de l’expéditeur afin de faire croire que le message provient d’une source fiable — souvent une entreprise connue. Leur objectif ? Tromper le destinataire pour l’amener à cliquer sur un lien malveillant ou à divulguer des informations sensibles.
Dans cet article, nous allons vous expliquer comment fonctionne le spoofing d’e-mail, les risques qu’il représente et, surtout, les actions que vous pouvez mettre en place pour protéger votre entreprise et vos clients.
À quoi ressemble un e-mail spoof ?
Voici les éléments clés à surveiller pour identifier un e-mail spoofé :
- Spoofing du nom d’affichage : un e-mail où le nom d’affichage est identique ou très proche de celui d’un employé réel de l’entreprise. Cela crée un faux sentiment de légitimité.
- Spoofing du domaine : l’expéditeur falsifie non seulement le nom d’affichage, mais aussi le nom de domaine de l’entreprise. L’adresse e-mail semble alors provenir du domaine officiel, rendant la fraude plus difficile à détecter.
- Adresse de l’expéditeur suspecte : c’est souvent un indice révélateur. Même si le nom d’affichage peut sembler familier, le domaine qui suit le symbole “@” est souvent différent ou étrange. Cela trahit généralement une tentative de spoofing.
- Un ton pressant ou menaçant : les cybercriminels utilisent souvent un langage alarmant pour pousser le destinataire à agir rapidement, sans prendre le temps de réfléchir. Cela peut inclure des menaces ou une fausse urgence.
- Promesses de gains ou de cadeaux : ces e-mails prétendent souvent que vous avez gagné un prix ou une récompense. Cela pousse les victimes à fournir des informations personnelles ou à cliquer sur des liens ou pièces jointes malveillants pouvant infecter leurs appareils.
- Incohérences visuelles : certains e-mails spoofés présentent des logos obsolètes, des fautes de mise en page ou un format différent des communications habituelles de l’entreprise. Bien que les fraudeurs deviennent de plus en plus habiles à imiter le style visuel, certaines tentatives restent faciles à repérer.
Stopper le spoofing d’e-mail : les bonnes pratiques à connaître
Le spoofing d’e-mail peut être limité, voire empêché, en configurant plusieurs mécanismes d’authentification comme SPF, DKIM et DMARC. Chacun joue un rôle distinct dans la vérification des messages, mais c’est leur mise en œuvre conjointe qui permet de protéger efficacement votre domaine contre les tentatives de spoofing.
Sender Policy Framework (SPF)
SPF est un protocole d’authentification des e-mails conçu pour vérifier l’identité de l’expéditeur.
Pour mettre en place SPF, vous devez déclarer les adresses IP ou serveurs de messagerie autorisés à envoyer des e-mails en votre nom. Lorsqu’un e-mail est reçu, le serveur de réception interroge le serveur DNS du domaine pour vérifier si l’adresse IP de l’expéditeur figure bien parmi celles autorisées. Si ce n’est pas le cas, le message peut être marqué comme suspect ou bloqué.
L’e-mail n’est délivré dans la boîte de réception du destinataire que s’il provient d’une adresse IP autorisée et s’il réussit la validation SPF. En configurant correctement les enregistrements SPF, vous pouvez améliorer la délivrabilité de vos messages, réduire les risques de spam et prévenir l’usurpation d’adresse e-mail.
DomainKeys Identified Mail (DKIM)
DKIM est une signature numérique ajoutée à chaque e-mail que vous envoyez. Elle fonctionne en complément des enregistrements SPF.
En plus de vérifier l’authenticité de l’expéditeur, DKIM permet de s’assurer que le contenu du message n’a pas été altéré ou modifié pendant son acheminement. C’est un moyen efficace de garantir l’intégrité des e-mails et de renforcer la confiance des destinataires.
Pour configurer DKIM, il faut publier une clé publique dans les enregistrements DNS de votre domaine. Lorsqu’un e-mail est envoyé, votre serveur génère une empreinte numérique du message (incluant le contenu et les titres) et la signe à l’aide d’une clé privée, qui reste confidentielle.
Lors de la réception, le serveur du destinataire utilise la clé publique pour vérifier si cette signature est bien authentique. Si l’empreinte correspond, cela signifie que le message n’a pas été altéré pendant son envoi.
Cette méthode garantit l’intégrité de vos e-mails et empêche les attaquants de se faire passer pour vous, puisqu’ils ne possèdent pas la clé privée nécessaire pour signer les messages.
DMARC (Domain-based Message Authentication, Reporting and Conformance)
DMARC est une méthode d’authentification avancée conçue pour prévenir le spoofing e-mail. Elle repose sur les protocoles SPF et DKIM, et permet de définir une politique claire à appliquer lorsqu’un message échoue à ces vérifications.
Concrètement, DMARC vous permet de publier une politique dans votre DNS indiquant aux serveurs de messagerie des destinataires quoi faire lorsqu’un e-mail ne passe pas les contrôles SPF ou DKIM. Trois actions sont possibles :
Action 1 : Aucune action
Aucune mesure n’est prise, même si le message échoue aux vérifications SPF ou DKIM.
L’e-mail est quand même transmis dans la boîte de réception du destinataire.
Action 2 : Quarantine
L’e-mail est livré, mais redirigé vers le dossier des spams ou courrier indésirable, car il n’a pas passé les contrôles SPF/DKIM.
Action 3 : Rejeter
Si cette politique est choisie, tout e-mail qui échoue aux vérifications SPF ou DKIM est simplement rejeté. Il ne sera jamais livré au destinataire.
Comment Zoho Campaigns vous aide à prévenir le spoofing d’identité par email et à protéger votre domaine
Zoho Campagins permet à chaque utilisateur de configurer facilement les enregistrements SPF et DKIM afin d’authentifier son domaine.
Si un email réussit les vérifications SPF et DKIM, la politique DMARC ne s’applique pas. En revanche, si l’une de ces vérifications échoue, le serveur de réception consulte alors la politique DMARC du domaine pour déterminer comment traiter le message. Il est important de noter qu’une politique DMARC ne peut être activée qu’après la mise en place des enregistrements SPF et DKIM, sans quoi la validation DMARC échouera.
Une fois l’authentification SPF et DKIM configurée pour votre domaine, vous pouvez définir la politique DMARC dans les enregistrements DNS de votre domaine. Vous pouvez en apprendre davantage sur la configuration des enregistrements DMARC ici.
Configurer SPF et DKIM permet non seulement de lutter contre spoofing e-mail, mais aussi d’améliorer la délivrabilité de vos messages. En plus de SPF et DKIM, Zoho Campaigns propose également plusieurs fonctionnalités axées sur la délivrabilité, afin d'assurer que vos emails atteignent toujours la boîte de réception.
E-mail spoofing évolue constamment, et rester passif face à cette menace peut entraîner des pertes financières ou nuire à la réputation de votre entreprise.
En mettant en place de manière proactive des protocoles d’authentification email tels que SPF, DKIM et DMARC, les entreprises peuvent réduire considérablement les risques liés à l’usurpation d’identité par email.
L'équipe Zoho France
Access your files securely from anywhere
New to Zoho Recruit?
Zoho Developer Community
New to Zoho LandingPage?
Zoho LandingPage Resources
New to Zoho Survey?
New to Zoho CRM Plus?
Deliver unforgettable customer experiences
New to Zoho CRM Plus?
Deliver unforgettable customer experiences
New to Zoho Marketing Plus?
Everything you need to run your marketing
New to Zoho Marketing Plus?
Everything you need to run your marketing
New to Bigin?
Topic Participants
Kinjal Lodaya
Sticky Posts
Collaboration sans faille avec Zoho One
Bonjour à tous, Dans cet article nous allons voir comment Zoho One permet une collaboration à différents niveaux . La façon dont nous travaillons évolue. À mesure que les entreprises se mondialisent, la plupart des activités sont menées en équipe.
New to Zoho TeamInbox?
Zoho TeamInbox Resources
Zoho CRM Plus Resources
Zoho Books Resources
Zoho Subscriptions Resources
Zoho Projects Resources
Zoho Sprints Resources
Qntrl Resources
Zoho Creator Resources
Zoho CRM Resources
Design. Discuss. Deliver.
Zoho Show Resources
Get Started. Write Away!
Writer is a powerful online word processor, designed for collaborative work.
Zoho CRM コンテンツ
-
オンラインヘルプ
-
Webセミナー
-
機能活用動画
-
よくある質問
-
Ebook
-
-
Zoho Campaigns
- Zoho サービスのWebセミナー
その他のサービス コンテンツ
Nederlandse Hulpbronnen
ご検討中の方
Recent Topics
Writing on sketch cards is bugged when zoomed in
When zoomed in, it writes a noticeable distance above or to the side of where you're actually trying to write. The further you're zoomed in, the more noticeable it is. Zooming is also entirely absent on the desktop version.Swipe between notes on iPhone
It'd be convenient if I could move from one note to the next in a notebook simply by swiping left to right.Sales IQ chat is not working in signed android apk
I have integrated ZOHO sales IQ support chat and i have followed each step and its working fine in my development build but when i create signed APK for it. Chat does not work in it and showing awaiting for detail. I previously asked the same query butCOQL order by COUNT not working
Dear community, I am trying to get a list of deal amounts per planner working on it and sorted to get see who has the least amount of deals. For some reason, I am unable to use sort by in combination with a COUNT. My original code was: query = "selectI want to duplicate a report and name it something else
Hi, I have created a report, and now want to reproduce it and call it something else. so that I will end up with TWO separate reports with different titles. Please tell me how do I copy / reproduce a report pleaseZoho CRM: Sales Rep Professional Certification Program on Coursera
We are happy to share that we have published the Zoho Sales Representative Professional Certificate in partnership with Coursera, a leading platform for online learning and career development that offers access to courses and degrees from leading universitiesOS X Notebook quits immediately upon launch
NoteBook for OS X (Sequoia, but also under Sonoma) always quits immediately upon launch (so I cannot use the "Attach user log" option). I've restarted my MacBook but the problem persists. If it helps, attached is a diagnostic report from Library>LogCan External users upload files or images to WorkDrive?
I want to know if it is possible for someone externally through a link and PW be able to upload files and images onto WorkDrive?Multi-line fields character limits
Is there a way to set the character limit higher on multi-line fields so that we are not losing information pasted into the field? When the text is entered or pasted, there is no error to say that the text is too large. After saving and going back to view most of the text is gone. Also, when viewing the resume, the text is not wrapped in the multi line fields and can t be read without scrolling across the page.Taz bot not working — What should I do to resolve this issue?
I am experiencing issues with the Taz bot in Zoho Cliq—not receiving responses or it does not seem to work as expected. Could you please explain why the Taz bot might not be functioning and what steps I should take to resolve this issue? Thank you!OneNote Migration
I am trying to migrate two notebooks from OneNote. For five days now I have had no notification that migration has completed and the migration page show 50% complete - one notebook completed one not finished. It just stays like this. I am unable to cancelSet various time slot reminders for task and event
Hi I would like known if there is possibility to set various time reminders for a task or event like we have the possibility to do in google calendar or google task. For example I'am creating an event or task and I want to be alerted before 30min andZoho Calendar not functioning---cannot edit, add attendees, etc.
Hello, My calendar is acting strange. I'm using Chrome as my browser and pop ups are not blocked (the calendar worked fine yesterday). When creating an event, I'm not able to "edit" the event and add attendees, etc. The link is non-responsive. I cannotSpilt Axis for stacked column and line graph
Each month around this time I prepare a business review deck. One of the biggest annoyances I have with Zoho, also happens to be something that most other platforms have provided for a long time now, and that is being able to create a chart with stackedPin a note on top
Dear Zoho Notebook Team, Please highly consider adding ability to pin a note on top and arrange pinned notes. I have a lot of notes that I want to pin important ones on top and this feature is missing badly. Thank you.Windows 11 app ver 2.2.8
I have been trialing Zoho Notes syncing between my PC and iphone. No problems with iphone but the Windows 64 bit app ver 2.2.8 was very buggy and would lock up completely, needing a Control Alt Delete etc to close it down. It seemed to be connected toDeluge Script: Onboarding → Access Form
Hello everyone, Edit: Sorry, I think I put this topic in the wrong section. I’ve recently run into an issue that’s been giving me a bit of a headache for the past few weeks. Context: This is my first time using Deluge to create a script, but it’s notWindows Device Authentication
We have recently started using ManageEngine, and my boss saw a device management feature in the Zoho One directory. We thought it would either help give us more intergration into Zoho one through bringing ManageEngine services through Zoho one. Or, itHow can I change spell check language?
I cannot find the way to change spell check language. My "display language" is English, and I want to have the same one for Spell Check, but it is Russian!!! How can I change it? In one of your explanations you mentioned that I have to choose it fromMail is so slow - doesn't even work!
Mail has been getting slower and slower - and today it's not even pulling up emails in either Inbox or Unread. This is beyond frustrating since email is a big part of business. Sent a request through the useless help portal - no response. Called the uselessUser marked as SPAMMER. Mail Fetch has also been disabled for any active POP accounts.
I am the administrator for joelles.com One of our accounts has been blocked saying this: User marked as SPAMMER. Mail Fetch has also been disabled for any active POP accounts. I cannot change the disabled account in the control panel as it says that itMy domain did not activate
Hi, my domain (apsaindustrial.com.ar) did not activate, and the phone verification message never arrived. Please would you solve this problem? Thanks.ME SALE ESTE ERROR: No fue posible enviar el mensaje;Motivo:554 5.1.8 Email Outgoing Blocked
Ayuda!! Me sale este error al intentar enviar mensajes desde mi correo electronico de Zoho! Tampoco recibo correos pues cuando me envia rebotan. Ayuda, Me urge enviar unos correo importantes!! Quedo atenta MAGDA HERNANDEZ +5731120888408Is there a way to sync Tags between CRM and Campaigns/Marketing Hub?
I wonder if there is a way to synch the tags between CRM and Marketing-Hub / Campaigns?how to see if a specific contact opened an email in zoho campaign?
how to see if a specific contact opened an email in zoho campaign?Revenue Management: #8 Revenue Recognition in Educational & Training Institutions
Educational Institutions and training centres typically collect course fees at the time of enrolment, sometimes for a one-day workshop and sometimes for a year-long certification course. You might also charge separately for course materials or evaluation.How to Customize Task Creation to Send a Custom Alert Using JavaScript in Zoho CRM?
Hello Zoho CRM Community, I’m looking to customize Zoho CRM to send a custom alert whenever a task is created. I understand that Zoho CRM supports client scripts using JavaScript, and I would like to leverage this feature to implement the alert functionality.Maximum file limit in zoho people LMS
Dear Team, I am having approximately 4.9 GB of material, including PPTs and videos for uploading in zoho people LMS course. May I know what is the maximum limit limit for the course files Thanking you, With regards, Logeswar V Executive _ OperationsDynamically prefill ticket fields
Hello, I am using Zoho Desk to collect tickets of our clients about orders they placed on our website. I would like to be able to prefill two tickets fields dynamically, in this case a readonly field for the order id, and a hidden field for the sellerOptimize your Knowledge Base for better visibility by allowing search engine crawling and indexing
All you need to know about no-follow and no-index in KB. What are article crawlability and indexability? Crawlability and indexability are vital for making an article visible and accessible to search engines. When a search engine crawls an article, itHas anyone created a public ASAP Guide that I can check out?
I am thinking of adding an ASAP guide to my web application, but I have noticed that the ASAP widget itself can be really slow to load sometimes. Has anyone created a public ASAP Guide that I can check to see how performant it is? I don't want to spendWhat’s New in Zoho Analytics – September 2025
Hello Users!! In this month’s update, we’re raising the bar across multiple touchpoints, from how you bring in data, plan and track projects to how you design and brand your dashboards. We’ve added the all-new Gantt chart for project visualization, expandedZoho MCP has no tools for Creator or 3rd Party Apps?
I don't see a Zoho MCP community forum so putting this here. Two big problems I see: 1) Although Zoho advertises "over 950 3rd party apps" as available through their MCP, when I go to "Add Tools" there are ZERO 3rd party apps available to choose from.Zoho Forms - Zoho Drive connection - Shared Drives not supported
Hello i am stuck with Google Drive Connection There is no supported shared drives Connection is not support shared drives boolean Query Parameters - supportsAllDrives=true&supportsTeamDrives=true to activate fetch files from the shared drives. Ahat needCan't create package until Bill created?
I can't understand why we cannot create a package until a Bill is created? We are having to created draft Bills to create a package when the item is received, but we may not have received a Bill from the supplier. Also, Bill # is required, but we normallyWhats the Time out Limit for API Calls from Deluge?
Hi Creator Devs, We are making API calls to third party server via Deluge. Getting this error message: Error at line : 24, The task has been terminated since the API call is taking too long to respond. Please try again after sometime. Whats the defaultHow to get the authorization code for domain transfer from Zoho?
I have transferred my domain from zoho to godaddy, and that needs a authorization code. I haven't got any mail containing that. How to get the authorization code from domain transfer? Thanks, ArunHow can I optimize a Zoho Site page for SEO when embedding external menu or restaurant links?
Hi everyone, I’m experimenting with building small content hubs on Zoho Sites and want to make sure I’m doing it in an SEO-friendly way. For example, I tried creating a page that highlights restaurant menu items and linked out to a resource like this:Diff signature for compose new email and replies
Hi, How do i have different signature for replies and new emails. its inconvenient to have one large signature for replies. Usually on Outlook we have the option to keep separate signatures for new emails and for replies.Zoho Website Site Speed Up & Setting
We are experiencing slow loading speeds on our Zoho website and would like assistance in optimizing its performance. Kindly review the site and suggest or implement necessary improvements to enhance speed, especially related to: > Caching mechanisms >Next Page