AS(42004) Outbound Sender Restriction Not Removed

Question

Outbound email from [Moderator note: Personally Identifiable Information removed]@fiberdresser.com is still blocked with error: 550 5.1.8 Access denied, bad outbound sender AS(42004). The sender was already reviewed/cleared from Restricted entities, but the issue persists for more than 24 hours. Please investigate and remove any remaining outbound sending restriction.

Answer 1

Hi Anowar,

According to Remove blocked users from the Restricted entities page - Microsoft Defender for Office 365 | Microso…, under most circumstances, all restrictions should be removed from the user within one hour. Transient technical issues might cause a longer wait time, but the total wait should be no longer than 24 hours.

Given the nature of the problem, the most effective next step is ruse your admin credentials to submit a support request through the Microsoft 365 Admin Center.

Microsoft also provides customer service phone numbers based on your region. You can find the appropriate contact number here: Customer service phone numbers - Microsoft Support 

This route ensures that a Microsoft support engineer can initiate a remote session to investigate backend configurations, run advanced diagnostic tools, and, if necessary, you can request to escalate the case to specialized teams with access to internal systems and logs. These backend resources are essential for resolving issues that go beyond what’s visible in the user interface.

I hope this helps you resolve the issue quickly. I’m glad to assist and truly hope the information provided has been useful. Please feel free to reach out anytime if you need further assistance.  

If you find my post helpful, kindly consider marking it as the accepted answer. Doing so can assist others in the community who may have similar questions in finding solutions more quickly.  

Thank you for your kindness and contributions to the forum.