Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi Bismarkp,
This issue was posted to the Service Health Dashboard (SHD) as incident EX196384 starting at November 21 2019 21:08 PM (UTC). The user experience of this incident is: Users may be unable to delist IP addresses identified as spam through sender.office.com.
More info: Users won't be able to validate the Captcha request successfully.
Tenant administrators can view current information and updates on SHD at the link here
https://portal.office.com/admin/default.aspx#@/ServiceStatus/ServiceStatusHistory.aspx
For affected customers to easily identify the information here, this thread will be closed. We will update to the primary thread below once the issue is resolved or you can obtain the most recent information from SHD. For your reference
If you are experiencing a similar issue and do not see an SHD post, please let us know by sharing your tenant information via Private Message (PM).
Regards,
Oliver