5.7.708 Microsoft bounce: IP not accepted

What 5.7.708 means

Exchange Online is refusing traffic from this sending IP address for the tenant.

Message text

5.7.708 Access denied, traffic not accepted from this IP

Common causes of 5.7.708

• Sending IP is blocked for the tenant after abuse detection

How to fix 5.7.708

1. Make sure no account is compromised and no open relay exists.
2. Check the sending IP with blocklist check.
3. Contact Microsoft support through your regular channel.

Check your domain

Read the headers of a bounced messageRuns in your browser; nothing is uploaded.

Have the full bounce message? Paste it into the bounce code lookup and it will match the code and the provider for you. Open the bounce code lookup.

How to read 5.7.708

The second part, 5.7.708, is an enhanced status code (RFC 3463 §2) written class.subject.detail. Class 5 is a Permanent failure (5xx): the command was rejected and the sender should not repeat it unchanged (RFC 5321 §4.2.1; RFC 3463 §2).. Subject 7 is security or policy: authentication, authorization or policy refused the message. The detail number refines the subject, and providers may define details of their own, which is why one code can read differently at Gmail, Microsoft and Yahoo.

Do not keep resending the same message: a permanent failure repeats until the cause is fixed. Correct the cause, then send a new message.

Official source: learn.microsoft.com. Last verified 2026-10-20.

Related guides

• Reverse DNS (PTR) for mail servers: how to set it
• How to create an SPF record (syntax and examples)
• How DKIM works and how to publish a DKIM record

Related codes

• 5.7.0 SMTP: security status
• 5.7.1 SMTP: delivery not authorized
• 5.7.23 SMTP: SPF validation failed
• 5.7.25 SMTP: reverse DNS failed
• 5.7.26 SMTP: authentication failed
• 5.7.27 SMTP: sender has null MX

FAQ

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