[WEBHOSTING] New email security measures

Incident Report for Scaleway

Investigating

Following the implementation of new email security measures, it is no longer possible to send messages via SMTP using a sender address that is different from the one used for authentication.

This change is intended to enhance security and improve the deliverability of your emails by preventing identity theft.

If you encounter a 550 ‘Authenticated sender mismatch’ error, please check that the email address configured as the sender in your email client matches the one used to connect to the SMTP server.

Posted Nov 27, 2025 - 13:13 CET

This incident affects: Dedibox - Products (Hosting).