L'Afnic est présente aujourd'hui jusqu'au 3 avril au Forum INCYBER Europe (FIC) au stand F-40 à Lille.
Une belle opportunité d'échanger sur les enjeux DNS de la cybersécurité.
Découvrez également notre nouvelle formation NIS 2 Lead Implementer https://www.afnic.fr/produits-services/formations/formation-nis-2-lead-implementer/
Et explorer toutes nos formations sur la sécurisation du DNS https://www.afnic.fr/produits-services/formations/
Venez rencontrer Lotfi Benyelles, Benoît Ampeau et Régis Massé au Stand F-40 !
Apparently, their 
![Screenshot from part of https://www.security.nl/posting/766069/DMARC+bypass+%28Outlook+only%3F%29#posting767981
Microsoft has meanwhile changed this behavior, but https://docs.microsoft.com/en-gb/microsoft-365/security/office-365-security/use-dmarc-to-validate-email#how-microsoft-365-handles-inbound-email-that-fails-dmarc used to read:
{
How Microsoft 365 handles inbound email that fails DMARC
If the DMARC policy of the sending server is p=reject, Exchange Online Protection (EOP) marks the message as spoof instead of rejecting it. In other words, for inbound email, Microsoft 365 treats p=reject and p=quarantine the same way.
[...]
Microsoft 365 is configured like this because some legitimate email may fail DMARC. For example, a message might fail DMARC if it's sent to a mailing list that then relays the message to all list participants. If Microsoft 365 rejected these messages, people could lose legitimate email and have no way to retrieve it. Instead, these messages will still fail DMARC but they'll be marked as spam and not rejected.
If desired, users can still get these messages in their inbox through these methods:
• Users add safe senders individually by using their email client.
[...]
}](https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/214/347/096/179/983/original/387331c3ef4e4af2.jpeg "Screenshot from part of https://www.security.nl/posting/766069/DMARC+bypass+%28Outlook+only%3F%29#posting767981
Microsoft has meanwhile changed this behavior, but https://docs.microsoft.com/en-gb/microsoft-365/security/office-365-security/use-dmarc-to-validate-email#how-microsoft-365-handles-inbound-email-that-fails-dmarc used to read:
{
How Microsoft 365 handles inbound email that fails DMARC
If the DMARC policy of the sending server is p=reject, Exchange Online Protection (EOP) marks the message as spoof instead of rejecting it. In other words, for inbound email, Microsoft 365 treats p=reject and p=quarantine the same way.
[...]
Microsoft 365 is configured like this because some legitimate email may fail DMARC. For example, a message might fail DMARC if it's sent to a mailing list that then relays the message to all list participants. If Microsoft 365 rejected these messages, people could lose legitimate email and have no way to retrieve it. Instead, these messages will still fail DMARC but they'll be marked as spam and not rejected.
If desired, users can still get these messages in their inbox through these methods:
• Users add safe senders individually by using their email client.
[...]
}")
