Email Service Providers & Infrastructure Comparisons
Navigating the Nuances of the Comcast Complaint Feedback Loop
2025/08/29 by Maarten Oelering.
For email senders, a Feedback Loop (FBL) is an indispensable tool for maintaining a healthy sender reputation. It provides direct feedback from mailbox providers when a recipient marks an email as spam. One of the key FBLs in the email ecosystem has been from Comcast, a major internet service provider in the United States. However, […]
Laposte.net tightens its requirements for email authentication
2025/08/25 by Yves-Marie Le Pors-Chauvel.
On Friday, August 22, in a message shared by Simon Bressier, Postmaster of Laposte.net, the mail provider announced a major shift in its deliverability and anti-spam policy starting in September 2025. The French webmail confirmed that email authentication standards (SPF, DKIM, and DMARC) will no longer be optional. Until now, some emails without authentication protocols […]
Categories: Authentication, DMARC, Providers
Orange Spain Announces the End of Its Email Services: What All Senders Need to Know Ahead of September 5, 2025
2025/07/04 by Yves-Marie Le Pors-Chauvel.
Orange Spain has officially announced the permanent shutdown of all its email services as of September 5, 2025. What will happen on September 5? All accounts will be permanently closed and deleted—without exception. Even end users will no longer be able to access their messages! This announcement affects anyone using one of the following 17 […]
Categories: Deliverability, Providers
Unlock Peak Performance: Postmastery's Q1 2025 Email Delivery Benchmark is Here
2025/07/03 by Yves-Marie Le Pors-Chauvel.
We are thrilled to announce the release of Postmastery’s  Email Delivery Benchmark Q1 2025. This essential study, conducted from January to March 2025, offers a refined analysis incorporating billions of email transactions to deliver an even more robust and comprehensive overview of email performance. What can you find inside? In this edition, we evaluate the most recent delivery trends […]
Categories: Deliverability, Providers
Outlook Deliverability: A Silent Shift with Serious Consequences
2025/06/20 by Yves-Marie Le Pors-Chauvel.
Starting on June 17th, 2025 at 11:10 UTC, multiple high-volume senders – particularly in France – began experiencing a sudden surge in DKIM failures on emails sent to Microsoft domains (Outlook, Hotmail, etc.). These bounces occurred even though SPF and DMARC were properly configured. UPDATE – July, 10 2025 Since the original publication of this […]
Categories: Authentication, Deliverability, Providers
SFR Deliverability: Explaining error codes (GU_EIB) and the ongoing error threshold
2019/10/07 by Jérôme Gays.
Before getting to the actual matter, it is important to brush upon a few relevant chronological events in the past regarding SFR. Even though SFR has been carrying this name since 1987, the many other departments in this group have changed quite a lot ever since. During the past 10 years, SFR has made the […]
Categories: Deliverability, General, Providers
Check your (Power)MTA settings: Numericable and Noos MXs records moved to SFR
2019/09/04 by Jérôme Gays.
In 2014, French ISPs Numericable and SFR merged to become the Altice France group. Numericable was itself the result of a merger between NC Numericable and Noos in 2007. Up to now, mailboxes at these ISPs were managed independently using different MXs and anti-spam protection. Noos and Numericable domains on one end and SFR domains […]
Categories: Authentication, Deliverability, General, Postfix, PowerMTA, Providers