How to Remove IP from Microsoft's Blacklist Print

When you send email to Microsoft's network (e.g. live.com, outlook.com, hotmail.com, Microsoft.com) and you receive a return message with error code 550.5.7.1, or something like below:

Action: failed
Final-Recipient: rfc822;[email protected]
Status: 5.0.0
Remote-MTA: dns; live-com.olc.protection.outlook.com
Diagnostic-Code: stmp; 550 5.7.511 Unfortunately, messages from [xxx.xxx.xxx.xxx] weren't sent. Please contact your Interne service provider since part of their network is on our block list (S3150).

It could be your IP/domain trapped within Microsoft's spam filters. It you confident that you're not running spamming/malicious activity on your server, you may try to request delist via below methods:

1) https://sender.office.com/

2) https://olcsupport.office.com/

3) email to [email protected] by include your domain and IP address

Follow screen instruction and fill in all requested information for method 1 & 2, submit and wait for the respond from Microsoft. If the initial respond is negative and your request is rejected, you may reply to them with evidence of your usage activity and justify why they should remove your IP from block list.