S3150 error

U T 0 Reputation points
2026-01-17T17:57:11.3166667+00:00

Hello,

The emails from my website sending to any hotmail/outlook address get rejected by "S3150" code. All is fine with the configuration of mail server of my domain

Please advise me what to do

Best regards,

Outlook | Web | Outlook.com | Email
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  1. EmilyS726 245.7K Reputation points Independent Advisor
    2026-01-17T18:32:41.26+00:00

    Hello

    Without seeing the full error message, it is hard to tell you why. It can be dns record issue, or bad IP.

    Can you please share the bounce email? It contains important diagnostic data that helps shed some light of the root cause. Feel free to redact personal information when you share.

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  2. AI answer

    2026-01-17T17:57:20.0366667+00:00

    The S3150 error typically indicates that the emails sent from your domain are being rejected due to a problem with the sender's reputation or configuration. Here are some steps you can take to troubleshoot and resolve this issue:

    1. Check DNS Records: Ensure that your domain's DNS records are correctly configured. This includes having valid A and MX records, as well as a reverse DNS (PTR) entry that matches your sending IP address.
    2. SPF Records: Make sure that you have a valid SPF (Sender Policy Framework) record set up for your domain. This record helps to prevent spoofing and ensures that your emails are recognized as legitimate by recipient servers.
    3. DKIM Signing: If possible, enable DKIM (DomainKeys Identified Mail) signing for your outgoing emails. This adds a layer of authentication and can improve your email deliverability.
    4. Monitor Sending Patterns: If your domain has been sending a high volume of emails, especially to Hotmail/Outlook addresses, it may have triggered spam filters. Monitor your sending patterns and reduce the volume if necessary.
    5. Contact Microsoft Support: If the issue persists, consider reaching out to Microsoft support for further assistance. They may provide specific insights related to the S3150 error and your domain's reputation.

    By following these steps, you should be able to identify and resolve the issue causing the S3150 error when sending emails to Hotmail/Outlook addresses.

    References:

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

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