550 5.7.511 Access denied, banned sender, Microsoft support says no - Microsoft Community

split thread.

we have problem now... no solution, same runaround. frustrating.

hi agent314,

 

in situation, i suggest use administrator account( if not admin, involve admin )to log into exchange admin center. and click protection> action center to check if blocked. here article reference:

removing user, domain, or ip address block list after sending spam email.

if admin delisted user no avail, further analysis, please provide tenant information , whole ndr via the private message.

 

thanks,

amanda

Office / Outlook / Other/unknown / Office 365 for business