SFR Deliverability: Explaining error codes (GU_EIB) and the ongoing error threshold

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 […]

Read more

Categories: Deliverability, General, Providers

Check your (Power)MTA settings: Numericable and Noos MXs records moved to SFR

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 […]

Read more

Categories: Authentication, Deliverability, General, Postfix, PowerMTA, Providers

Delivery issues at LaPoste.net resolved

On Friday April 6, 2018, Postmastery’s Email Delivery Analytics detected serious delivery issues at LaPoste.net. The most frequent SMTP errors we detected were: 421 4.3.2 No system resources 421 4.3.2 All server ports are busy 451 4.7.1 Service unavailable – try again later 421 4.7.0 lpn-prd-vrin0xx Error: too many errors 421 4.4.2 lpn-prd-vrin0xx Error: timeout […]

Read more

Categories: Deliverability, General, Providers

There are many more interesting blogs by category for you to read.