APIM Managed Developer Portal invitation and password-reset emails are not being delivered

We are trying to use the Azure API Management managed Developer Portal to provide a third-party development partner with controlled access to our APIs and products.

The portal itself is working. Users can access the portal, view the APIs and products available to their groups, and test API operations. However, none of the Developer Portal account emails we have tested are being received, including:

• User invitation emails
• Account confirmation emails
• Forgot password/password reset emails

We do not know whether APIM is generating these messages and they are failing during delivery, or whether email generation is being suppressed at the Azure subscription level. We have not found any APIM logs, delivery status, or diagnostics that identify the cause.

We restored the originating email address to the Microsoft-managed @mail.windowsazure.com address, but the messages are still not being received. We also upgraded the APIM service from Basic to Standard, but that did not resolve the issue. APIM does not appear to support configuring a custom SMTP service for managed Developer Portal identity emails.

Microsoft documentation indicates that APIM email functionality can be restricted for certain Azure subscription offer or quota types. We also found references to a subscription-level setting named DisableEmailsForSubscriptionQuotaTypes. We do not know whether that setting applies to our subscription, and we have not found a customer-visible way to inspect it.

We attempted to open an Azure technical support request, but the Azure portal indicates that our current support plan does not include technical support.

Could Microsoft please clarify:

1. Is there a way to determine whether APIM is generating and attempting to send these emails, including delivery logs or failure diagnostics?
2. How can we determine whether our Azure subscription offer or quota type restricts APIM email functionality or whether DisableEmailsForSubscriptionQuotaTypes applies?
3. If a subscription-level restriction applies, how can we request review or removal without access to an Azure technical support plan?
4. Is there any supported way to configure custom SMTP for APIM managed Developer Portal identity emails?
5. Is there a supported method to send invitation and password-reset messages through our own service, such as an API, Event Grid event, or delegation endpoint?
6. What is Microsoft’s recommended production solution for an external partner Developer Portal that requires invitation or approval, group-based product access, and reliable self-service password recovery?

The APIs, products, groups, JWT validation, and Developer Portal access controls are working. Reliable account invitation and password recovery are the remaining production blockers.

We are not asserting that APIM email is disabled. We are trying to determine why the messages are not being delivered and what supported remediation or alternative architecture is available.

Thank you.