Mails not forwarded to Outlook.com - permanent error (550)

[wolfgang.wershofen]

What is the name of the domain?

wershofen.de

What is the error number?

permanent error (550)

What is the error message?

upstream (eur.olc.protection.outlook.com.) error: failed to initalize: Unknown error: permanent error (550): 5.7.1 Unfortunately, messages from [104.30.10.189] weren’t sent. Please contact your Internet service provider since part of their network is on our block list (S3150).

What is the issue you’re encountering

Mails are not forwarded from Cloudflare to outlook.com account

What steps have you taken to resolve the issue?

Checked the log messages on the email routing page and sent several test messages.

What are the steps to reproduce the issue?

Send an email to one of my defined target addresses

[wolfgang.wershofen]

This is since about 6 hours according to the delivery status logs. Prior to that, I received transient errors on every new incoming mail
“temporary error: Unknown error: transient error (451): 4.7.650 The mail server [104.30.8.137] has been temporarily rate limited due to IP reputation.”
Those mails were delivered on the second try.

[wolfgang.wershofen]

Mail forwarding to outlook.com seems to be up and running again since about 10 hours.
Issue seems to be resolved.