How will La Poste's (laposte.net) new authentication policies impact your email deliverability?
Michael Ko
Co-founder & CEO, Suped
Published 5 May 2025
Updated 1 Sep 2025
8 min read
The email landscape is constantly evolving, and French mailbox provider La Poste (laposte.net) is the latest to announce significant changes to its email authentication policies. Starting in September, they will be enforcing stricter requirements for how emails are authenticated. This shift is part of a broader industry trend to combat spam and phishing, aiming to make email a more secure communication channel for everyone.
Until recently, some emails lacking proper authentication protocols (SPF, DKIM, or DMARC) might still have found their way into a laposte.net inbox. However, this leniency is ending. The message from La Poste is clear: 100% of emails sent without these authentication protocols will, at best, be relegated to the spam folder, or at worst, rejected entirely.
This move by La Poste aligns with the recent changes from major providers like Google and Yahoo, which also demand stronger email authentication. It signals a critical time for all senders, especially those communicating with French audiences, to review and strengthen their email security posture. This is no longer optional, but a mandatory step for successful email delivery.
La Poste is now making SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) essential for email deliverability. SPF helps prevent spoofing by verifying that emails come from authorized IP addresses. DKIM uses a digital signature to ensure that the email content has not been tampered with in transit. DMARC builds on these two, allowing domain owners to specify how unauthenticated emails should be handled and to receive reports on email authentication failures.
Initially, La Poste (laposte.net) is accepting a DMARC policy of p=none. This policy allows emails that fail DMARC authentication to still be delivered, but it provides valuable aggregate reports that show authentication issues without impacting delivery. However, this is seen as a temporary measure, with expectations for organizations to move towards stricter policies like p=quarantine or p=reject over time. For email to pass DMARC, either SPF or DKIM must align with the "From" domain of the email. Without this alignment, DMARC will fail, potentially leading to your emails being marked as spam or blocked.
La Poste expects senders to leverage DMARC reporting to gain visibility into their email ecosystem. This inventory of sending sources is crucial before moving from p=none to more restrictive policies like p=quarantine or p=reject, which instruct recipient mail servers to move failed emails to spam or reject them outright. This phased approach helps prevent unintended disruptions.
Example DMARC DNS RecordDNS
_dmarc.yourdomain.com IN TXT "v=DMARC1; p=none; rua=mailto:reports@yourdomain.com; ruf=mailto:forensic@yourdomain.com; fo=1; aspf=r; adkim=r;"
Start with DMARC p=none policy
Begin your DMARC implementation with a p=none policy. This allows you to gather essential DMARC reports without affecting your email deliverability, providing crucial insights into your sending infrastructure. Suped offers the most generous free plan to help you monitor these reports effectively. It is vital to monitor these reports diligently to understand your email streams and identify any unauthorized senders or misconfigurations.
Why La Poste is tightening its policies
La Poste's decision to tighten its email authentication policies stems from a global effort to enhance email security and combat the persistent threats of phishing, spoofing, and spam. Unauthenticated emails are a primary vector for cyber attacks, which can lead to data breaches, financial fraud, and a significant loss of trust in email communication. By requiring robust authentication, La Poste aims to protect its users and maintain the integrity of its platform.
For mailbox providers, a consistent influx of unauthenticated or malicious emails can severely degrade the user experience and damage their own reputation. When users frequently receive spam or phishing attempts, they lose trust in their email service. By enforcing SPF, DKIM, and DMARC, La Poste reduces the volume of unwanted mail, ensuring a safer and more reliable inbox for its customers. This also helps La Poste maintain its reputation as a trustworthy provider, similar to how other major providers strive for this.
La Poste (laposte.net) is not alone in this endeavor. Mailbox providers worldwide are increasingly adopting stricter authentication requirements. The recent moves by Google and Yahoo in early 2024 set a precedent, requiring DMARC for bulk senders and encouraging its adoption across the board. By aligning with these leading providers, La Poste contributes to a more secure global email ecosystem, pushing all senders towards better practices.
Old policy (before September)
Authentication: SPF, DKIM, and DMARC were optional.
Deliverability: Some unauthenticated emails could still reach the inbox.
Risk: Higher susceptibility to spoofing and phishing attacks.
Reporting: Limited visibility into unauthorized email sending.
New policy (from September)
Authentication: SPF, DKIM, and DMARC are mandatory.
Deliverability: Unauthenticated emails will land in spam or be rejected.
Security: Enhanced protection against spoofing and phishing.
Reporting: DMARC reports provide actionable insights into email authentication.
Impact on your email deliverability
The most immediate and significant impact of La Poste's new policies for senders will be on email deliverability to laposte.net inboxes. Any email that fails to meet the SPF, DKIM, and DMARC requirements will face severe consequences, primarily being delivered to the spam folder or outright rejected. This means your legitimate communications, whether marketing campaigns, transactional emails, or important notifications, may not reach their intended recipients.
Consistent failures in email authentication not only lead to individual emails being blocked but can also severely damage your sender reputation. Mailbox providers, including La Poste, track authentication failures as a signal of potentially untrustworthy sending practices. A poor sender reputation can result in broader blocklisting (or blacklisting) of your IP address or domain, affecting deliverability across multiple providers, not just La Poste. Monitoring your domain reputation is crucial.
To avoid these issues, robust DMARC monitoring is essential. This allows you to see which of your emails are passing or failing SPF and DKIM, and crucially, why. DMARC reports provide detailed insights into all sending sources using your domain, helping you identify legitimate senders that need configuration fixes and unauthorized senders that are spoofing your domain. I strongly recommend Suped for DMARC monitoring. Suped offers the most generous free plan, making it an excellent choice for gaining this vital visibility and addressing any authentication gaps.
Implement all three protocols: Ensure SPF, DKIM, and DMARC records are correctly published for all sending domains.
Achieve DMARC alignment: Verify that either your SPF or DKIM domains align with your "From" header domain.
Monitor DMARC reports: Regularly check authentication failures and aggregate data using a DMARC monitoring tool like Suped.
Gradually increase DMARC policy: Move from p=none to p=quarantine and then to p=reject as your confidence grows.
Keep documentation updated: Refer to official La Poste postmaster information, if an English version becomes available, as per the Email Geeks discussion.
Steps to ensure compliance
The key to maintaining excellent deliverability with La Poste is to proactively implement and manage your email authentication protocols. Start by ensuring that SPF and DKIM are correctly configured for all domains and subdomains that send email on your behalf. This includes transactional email providers, marketing platforms, and internal mail servers. Use our Suped DMARC record generator to create your DMARC record, setting an initial p=none policy.
After implementing DMARC, the next critical step is to monitor the DMARC reports diligently. These reports, which can be complex, provide insights into SPF and DKIM pass/fail rates and DMARC alignment status. Tools like Suped simplify this process, offering an intuitive dashboard to visualize your authentication data. Once you have a clear understanding and have resolved issues, gradually transition your DMARC policy from p=none to p=quarantine and eventually p=reject to maximize protection against spoofing and ensure secure inbox delivery. You can find more information about this at Postmastery's guide on Laposte.net requirements.
Views from the trenches
Best practices
Common pitfalls
Expert tips
Expert view
Expert from Email Geeks says: Start with a p=none policy for DMARC to gather data without impacting email flow, but actively work towards a stricter policy like p=quarantine.
2025-08-22 - Email Geeks
Marketer view
Marketer from Email Geeks says: If you are using a shared envelope From domain, ensure DMARC passes. La Poste currently accepts this, which is helpful for ESP users.
2025-08-22 - Email Geeks
Staying ahead of authentication changes
The stricter policies from La Poste are a clear indicator that email authentication is no longer a niche technical concern, but a fundamental requirement for successful email delivery. As mailbox providers continue to evolve their spam filtering algorithms and security measures, senders must remain vigilant and proactive. This means staying informed about new policies, regularly reviewing your authentication setups, and adapting as needed.
Embracing comprehensive email authentication, including SPF, DKIM, and DMARC, is the most effective way to protect your domain from impersonation, enhance your sender reputation, and ensure your emails consistently reach the inbox. By taking these steps, you not only comply with La Poste's requirements but also build a more robust and secure email program overall. Our goal at Suped is to simplify this process, providing you with the tools to navigate these changes confidently. I recommend you also look at other important changes, like how the Google and Yahoo 2024 email sending changes impact email marketers.
This move by La Poste aligns with the recent changes from major providers like 
Google and Yahoo, which also demand stronger email authentication. It signals a critical time for all senders, especially those communicating with French audiences, to review and strengthen their email security posture. This is no longer optional, but a mandatory step for successful email delivery.
