Hi, I also believe it is not related to Sogo - but it is related to "Microsoft-Outlook-Protection" - WAN-IP or Block-of-WAN-IPs where your mailserver is hosting is listed on "Outlook-blacklist".
You can view and delist IP's on this link: https://sendersupport.olc.protection.outlook.com/snds/data.aspx Hope this helps... Br, Aris Dizdarević -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Marco Sent: Thursday, September 28, 2023 12:28 PM To: [email protected] Subject: Re: [SOGo] Email not being sent Am 27.09.2023 schrieb "\"Support\"" ([email protected]) <[email protected]>: > <[email protected]>: host > msn-com.olc.protection.outlook.com[104.47.59.161] said: 550 5.7.1 > Unfortunately, messages from [185.223.74.125] weren't sent. Please > contact your Internet service provider since part of their network is > on our block list (S3140). That is not related to SOGo at all. You send the mails out from 185.223.74.125. That host seems to be or has been on a blacklist MS uses. https://docs.hetzner.com/de/robot/dedicated-server/troubleshooting/microsoft -blacklist/ https://olcsupport.office.com/ is named as a place where you can delist it. Question 1: Is 185.223.74.125 your system or do you relay it through another SMTP server (often called smarthost)? If it is yours and only controlled by you: Check the logs for any spam message Be careful with this message: it is coming from an external sender Do not open attachments nor click on links, unless you are sure that the content is safe Scanned by Alcad Security System
