My outgoing emails keep getting flagged as SPAM. How do I fix that?

Bryan Silverman 5 Reputation points
2026-01-08T01:54:13.8433333+00:00

My outgoing emails are suddenly all getting flagged as SPAM. Even forwarding an email to my Gmail account gets flagged as SPAM. I can receive emails but I can't respond or send an email without it bouncing and being blocked as SPAM. I uninstalled Office 365 and re-installed it but the problem still exists.

Microsoft 365 and Office | Other

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  1. AI answer

    2026-01-08T01:54:23.8366667+00:00

    If your outgoing emails are being flagged as spam, there are several steps you can take to address the issue:

    1. Check Your Domain Reputation: Ensure that your domain is not on any blacklists. You can use tools like Microsoft’s Smart Network Data Services (SNDS) to monitor your domain's reputation.
    2. Remove Non-Existent Email Addresses: If you receive non-delivery reports (NDRs) indicating that certain email addresses are no longer in use, remove those addresses from your mailing list. This helps maintain a clean list and improves your sending reputation.
    3. Follow Proper Email Formatting: Ensure that your outgoing emails are formatted correctly. For instance, follow the format of bounce messages as specified in RFC 3464 when sending non-delivery reports.
    4. Use SPF, DKIM, and DMARC: Implement these email authentication methods to help verify that your emails are legitimate and reduce the chances of them being marked as spam.
    5. Monitor Sending Patterns: If a significant portion of your emails is identified as spam, you may be temporarily blocked from sending emails. Ensure that your email sending practices comply with best practices to avoid being flagged.
    6. Contact Your Email Administrator: If you are part of an organization, reach out to your email administrator for help. They can review settings and configurations that may be causing your emails to be flagged.

    By following these steps, you can improve the deliverability of your outgoing emails and reduce the chances of them being flagged as spam.

    References:

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