Threshold exceeded

Question

Hi. I am a small company and do not have an IT admin managing our accounts and emails. Today, all emails i send are getting rejected from my account with this error code 550 5.7.705 Service unavailable. Access denied, tenant has exceeded threshold. I can receive but not send. The below is the error and for the life of me i do not know how to resolve this. All my activities are legit and i regularly email my clients but today i got rejections multiple times

Diagnostic information for administrators:

Generating server: AS8PR08MB8969.eurprd08.prod.outlook.com

******@me.com
Remote server returned '550 5.7.705 Service unavailable. Access denied, tenant has exceeded threshold. For more information please go to http://go.microsoft.com/fwlink/?LinkId=526653 S(7136) [AS1PR08MB7498.eurprd08.prod.outlook.com 2024-01-30T07:50:09.336Z 08DC21071FAAA0E1]'

Original message headers:

Received: from AS8PR08MB8969.eurprd08.prod.outlook.com
 ([fe80::e092:56a5:1a22:45da]) by AS8PR08MB8969.eurprd08.prod.outlook.com
 ([fe80::e092:56a5:1a22:45da%3]) with mapi id 15.20.7228.029; Tue, 30 Jan 2024
 07:50:09 +0000
MIME-Version: 1.0
Content-Type: text/plain
Date: Tue, 30 Jan 2024 07:50:09 +0000
Message-ID: <******@noumena.me>
Subject: Teating

Answer 1

Did you follow the link in the error message?

With an additional reference, you'll end up here;
Fix NDR error 5.7.700 through 5.7.750 in Exchange Online - Exchange | Microsoft Learn

Use the reports to find out which outgoing emails got blocked and caused the tenant block for sending emails. Review these emails and take appropriate measures if needed (for instance, you have an open relay in your environment, a wrongly configured connector, or an account got compromised).

If these are all legitimate emails, open a support case from within the Microsoft 365 Admin panel, reference to the reports and state that these are all legitimate emails and that you want to open an investigation case as to why these were blocked and caused the tenant wide block.