As Exchange Online administrator, you may be already aware there has been a new and modern Exchange Online administration portal available (https://admin.exchange.microsoft.com/).
Well, the classic Exchange Online administration portal (https://outlook.office365.com/ecp) is going to be retired starting October 15, 2021 and will be fully removed by September 1, 2022.
Starting October 2021, features related to security (spam/phishing, safe links and attachments…) will be removed from the classic Exchange Online administration to be made available only from the Microsoft 365 Defender portal (https://security.microsoft.com/) under the Email & collaboration section.
Then starting December 15, 2021, mail flow features will be removed from the classic administration portal.
From January 2022 to August 2022, additional features will be removed from the classic portal to lead by September 30, 2022 to the full removal of the classic portal.
If you did started to use the modern Exchange administration portal as well the Microsoft 365 Defender portal, start familiarize yourself now.