outlook mail cannot send due to spam

Ann Pitcher 0 Reputation points
2026-08-19T16:39:18.68+00:00

My Outlook will not send any new messages. I have already changed my account password and I am logged in. The failure says it cannot deliver dude to suspected spam deliveries

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  1. AI answer

    2026-08-19T16:39:35.1866667+00:00

    This usually means the account was flagged for suspected spam activity and outbound sending is temporarily blocked.

    For Outlook.com, use this checklist:

    1. Secure the account first.
      • Since the password was already changed, also review recent sign-in activity.
      • Check the Sent folder for messages that were not created intentionally.
      • In Outlook.com settings, review Rules and Forwarding and remove anything unfamiliar.
    2. Check whether the send failure is related to a blocked sender status.
      • If the error says the sending address was "not recognized as a valid sender" or mentions suspected spam, that matches the blocked outbound sender condition.
    3. If using Outlook.com in the browser, also rule out common send blockers.
      • Remove any attachment larger than 25 MB.
      • If a signature is added automatically, remove it and try sending again.
      • Make sure the recipient address is correct.
    4. If mail was blocked after compromise or spam-like activity, sending may not resume immediately.
      • New Outlook.com accounts can have a temporary low sending quota until account credibility is established.
    5. If the account is a work or school Microsoft 365/Exchange account, this is usually not self-service.
      • The email administrator must check whether the account is on the Restricted entities page in Microsoft 365 Defender and unblock it.
      • After unblocking, restrictions are usually removed within one hour.
    6. If messages are still failing in Outlook.com, use Microsoft support options from the delivery-failure article.
    AI-generated content may be incorrect. Read our transparency notes for more information.

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  2. Hendrix-V 19,485 Reputation points Microsoft External Staff Moderator
    2026-08-20T01:01:16.38+00:00

    Hi Ann Pitcher,

    The error message suggests your account's outbound email activity may have been temporarily restricted after being identified as potential spam-like behavior. Since you've already changed your password, it would be helpful to determine whether the restriction is still active or if another factor is preventing messages from being sent.

    To help narrow this down, could you let us know:

    1. Are you using a personal Outlook.com account, or a work/school Microsoft 365 account?
    2. What is the exact error message or non-delivery report (NDR) you receive when sending?
    3. Does the issue affect all recipients, or only specific email addresses?
    4. Are you able to send a simple test message with no attachments and only a short subject/body?
    5. Have you noticed any unexpected messages in your Sent Items, or any email rules/forwarding settings that you did not create?

    The answers to these questions will help determine whether this is a temporary sending restriction, a sender validation issue, or another mail-delivery condition.

    I look forward to your update and will be happy to help you investigate further.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

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