Korzystanie z programu Outlook dla systemu Android na potrzeby zarządzania osobistymi pocztami e-mail i kalendarzami
Thank you for the info.
You can’t fix this on your side. You need to tell the sender (or their IT/provider) that Microsoft is blocking their sending IP 213.180.149.158 with S3150 and they must remediate and request delisting. This is exactly what Microsoft support threads describe for S3150 rejections.
Delist request can be made here, but needs to be made by sender, not you https://sender.office.com/
Or, they can also contact their ISP to ask to be put in a different IP range.