Resolving SMTP email delivery failures due to egress IP blacklisting
Outbound email delivery from Adobe Experience Manager as a Cloud Service can fail when the egress IP address is blocklisted by a third-party spam provider, causing SMTP servers to reject connections. To fix the issue, identify the egress IP, verify its blocklist status, request delisting, and adjust email delivery or relay configuration if needed.
Description description
Environment
Adobe Experience Manager as a Cloud Service (AEMaaCS)
Symptoms
- Outbound emails sent from AEM are not delivered.
- SMTP server logs show that connections from the AEM egress IP are rejected due to being listed as spam.
- The egress IP is confirmed to be blacklisted by a third-party provider.
- No error stack trace is generated in AEM logs, but SMTP server logs may indicate the rejection reason.
Cause
The egress IP used by your AEMaaCS instance is blacklisted by a third-party provider, causing SMTP servers that rely on this blacklist to reject outbound email. Adobe cannot directly control third-party blacklist providers, so remediation may require engagement with those providers.
Resolution resolution
To resolve this issue, follow these steps:
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Check your SMTP server logs for the source IP address of the connection attempts from AEM. If you do not have access to SMTP logs, consult your network or email administrator to determine the egress IP used by AEM for outbound email.
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Use a public blocklist lookup tool to verify whether the egress IP is listed.
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Visit the provider’s website and follow their process for requesting information or delisting the IP. Include details such as the egress IP address, the purpose of the IP (transactional email from AEMaaCS), and any relevant SMTP rejection logs when contacting the provider.
Use the following example template when reaching out:
code language-none "Hello, our service uses the IP [ your egress IP] for legitimate transactional email via Adobe Experience Manager as a Cloud Service. We have observed that this IP is currently listed on your blacklist, resulting in email delivery failures. Could you please provide information on the reason for the listing and the process for delisting? Thank you." -
Ensure your email templates and sending practices follow best practices to avoid triggering spam filters (for example, avoid excessive links, use proper headers, and include unsubscribe options if applicable).
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Consider using a third-party SMTP relay service that is not affected by the blacklist to send outbound email from AEMaaCS. Consult your organization’s IT or email team for guidance on configuring a different SMTP relay.
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After the IP is delisted or a new SMTP relay is configured, send a test email from AEM to confirm successful delivery.