outlook 365 business not working on 19 pc in our company since Monday outage

Glenn Hamilton 0 Reputation points
2026-09-04T18:00:05.63+00:00

unable to receive emails in outlook app and web we can send emails within our company and receive but no outside email we can not receive since Aug. 31st

Outlook | Web | Outlook on the web for business | Email
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  1. Ivory 1,075 Reputation points Independent Advisor
    2026-09-04T18:15:21.01+00:00

    Hi Glenn,

    To help troubleshoot this issue quickly, can you provide some additional information:

    1. When someone from outside (like a personal Gmail or Yahoo account) sends an email to your address, do they receive a bounce-back email (NDR)? If so, what is the exact error code or reason listed (e.g., 550 5.4.1, Host not found, or 4.4.7)?
    2. Is this happening to every single mailbox in your company, or only a specific person or team?
    3. Do you use an external spam filter or email gateway in front of Microsoft 365, such as Proofpoint, Barracuda, or Mimecast?
    4. Did your company make any changes to your domain DNS settings, domain renewal, or email licenses around August 31st?

    To ensure I provide the most accurate assistance, I would appreciate any additional information you can share regarding your current situation. If possible, please include screenshots, as they can be very helpful in the investigation.

    Thank you for your patience and understanding. Should you have any further questions, please feel free to contact me at any time.

    I look forward to your response.

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