Outlook will not successfully send messages.

Thistle Quilt Guild 0 Reputation points
2026-10-13T20:49:55.53+00:00

When sending a message I received the following error message:

  Remote server returned '554 5.7.0 < #5.7.520 smtp;550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)>'

I believe the solution might be to go to Settings in Outlook, then Mail, then Forwarding & IMAP. Once I enter the password, it wants to send a code to your email account. So of course I did not do that.

Could you do that for me, please?

Until this situation is resolved, I am unable to send any Guild emails.

Outlook will not process even a one word email without returning an error. I have another account and can send the same message with that account with no problem.

Outlook | Web | Outlook.com | Email

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  1. Hornblower409 16,820 Reputation points
    2026-10-14T14:26:02.9066667+00:00

    @Thistle Quilt Guild said

    I believe the solution might be to go to Settings in Outlook, then Mail, then Forwarding & IMAP. Once I enter the password, it wants to send a code to your email account. So of course I did not do that.

    That will not have any effect on your current problem.

    Outlook will not process even a one word email without returning an error. I have another account and can send the same message with that account with no problem.

    You do not have the normal AS(4810) problem, where Microsoft rejects only certain emails. For some reason Mother Microsoft has marked your account as a hard core spammer and is blocking anything you send.

    All I can suggest is that you bring in Microsoft Support so they can examine your account and remove the block.

    Outlook Web - Free In-App Support

    • Logon to https://outlook.cloud.microsoft/
    • From the main menu: Help -> ? Help
    • {This should open the Help side panel}
    • Search Help -> {Your problem} and press Enter
    • Still need help? [Yes]
    • If you get "We're here to help": Tell us your problem -> {Your problem, again} [Get Help]
    • [Sign In] {Use any Outlook/Microsoft account}
    • Choose a support option -> Chat with a support agent in your web browser

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  2. Brian Tillman 27,660 Reputation points Independent Advisor
    2026-10-13T21:37:57.7966667+00:00

    Hi. I'm Brian.

    In addition to what the AI said, keep in mind that Outlook.com is not well-suited to sending mass mail. It's easy to have the server start classifying your outgoing mail as spam. If you need to send multiple messages at one time, use a service suited to that, like Mailchimp or groups.io.

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  3. AI answer

    2026-10-13T20:50:08.7533333+00:00

    The verification step cannot be completed on someone else’s behalf.

    For the 554 5.7.520 Message blocked because it contains content identified as spam. AS(4810) error, the supported troubleshooting steps are:

    1. In Outlook on the web, remove any email signature temporarily.
    2. Change the message format to Plain text:
      • Select Settings
      • Go to Mail > Compose and Reply
      • Change the message format to Plain text
    3. Send a simple plain-text test message with no links or attachments.
    4. If that works, add content back gradually to identify what triggers the spam block.
    5. If sending to a group, try sending to a single recipient first to confirm whether the issue is related to bulk recipients.
    6. Check the account and complete any identity verification prompts for that account.

    The code being sent to the email account is part of the account verification flow and must be completed by the account owner.

    AI-generated content may be incorrect. Read our transparency notes for more information.

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