501 Connection rejected by policy 92603What does 501 Connection rejected by policy 92603 mean?
Policy 92603 is an internal rule identifier used by Cisco IronPort Email Security Appliances (the on-premises and cloud-hosted appliances Cisco markets to enterprise customers). When IronPort returns this rejection, your connection matched a specific policy rule the recipient organization configured: typically an IP reputation threshold (SenderBase score), a content filter pattern, a sender domain blocklist, or an HAT (Host Access Table) entry. The numeric policy ID is local to the recipient’s appliance: a different organization’s policy 92603 means something different. The fix path is to identify what triggered the match and address it, then contact the recipient postmaster for the specific rule.
Is this a soft or hard bounce?
The numeric policy is specific to the recipient’s IronPort appliance configuration. Reach out to the recipient organization’s email administrator to identify the rule and what triggered it.
Common causes
Cisco IronPort uses Talos SenderBase scoring. IPs below the recipient’s threshold get policy-rejected at connection.
Recipient admin added your domain to the appliance HAT or content filter block list.
Subject line, body, attachments, or links matched a Cisco SecureX or in-house content rule.
Some IronPort policies reject by country, ASN, or IP range as a baseline security posture.
How to fix it
Look up your sending IP at talosintelligence.com/reputation_center. Cisco IronPort weights this score heavily. If reputation is Poor or Neutral, that may be the cause.
Reach out to the recipient’s email administrator. Include the bounce text with policy 92603. They can look up the exact rule in their IronPort dashboard and confirm what triggered it.
Track sender reputation across multiple sources. Address any DNSBL listings. Reduce complaints. SenderBase score recovers over weeks of clean sending.
Provider-specific notes
| Context | Notes |
|---|---|
| Cisco IronPort C-Series and X-Series appliances | On-premises email security appliances widely deployed in enterprise environments. |
| Cisco Secure Email (formerly Email Security Appliance) | Cloud-hosted variant. Same policy engine, same numeric rule references. |
| Generic | Other appliances rarely return this exact wording. The 92603 numeric ID is a Cisco IronPort convention. |
Related error codes
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About the Author
Alaa · LinkedIn
Email infrastructure specialist with 8+ years of hands-on experience in SMTP, deliverability, and email verification. I’ve configured and troubleshot mail systems across Postfix, Exchange, and cloud relays, managed IP reputation and warmup campaigns, and built verification pipelines processing millions of addresses. My work spans DNS authentication (SPF, DKIM, DMARC, BIMI), bounce handling, blocklist monitoring, and compliance frameworks including CAN-SPAM and GDPR. I write every article on SMTPedia to give email professionals, developers, and marketers the accurate, RFC-grounded reference they need.
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