One of my users had my email server added to the outlook.com blacklist
[2023.10.11] 18:36:15.215 [24641966] RSP: 451 4.7.500 Server busy. Please try again later from [xx.xx.xx.197]. (S77719) [AM2PEPF0001C711.eurprd05.prod.outlook.com 2023-10-11T16:36:15.157Z 08DBC96CFF1F3A10]
Now I moved the outbound to another IP.
But on that IP I have a high reputation (sendscore 98 - cisco talos reputation ip good - ip reputation check by cyren: no risk). Furthermore, the IP is not on any blacklist.
Do you know how long we will have left? I can't find a way to request removal. do you know anyone?
I still find what happened crazy.
One of my users sent a message to a domain protected by prod.outlook.com with 10 recipients from the same domain. By default, this domain does not accept messages with multiple recipients. Not being able to communicate, my client thought it best to resend the message several times (3 times). Then he asked a colleague of his to do the same (always 3 times)
But does it seem normal to you that pro.outlook.com has blacklisted the server?
Sabatino Traini
Chief Information Officer