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Backoffice User Invitation Failures on Umbraco Cloud Projects

Projects hosted on Umbraco Cloud utilize a built-in infrastructure fallback mechanism to deliver backoffice user invitations without requiring manual SMTP configuration.

Written by Joana Knobbe

Product or Service: Umbraco CMS on Umbraco Cloud

Version: All versions

Issue: Users are unable to send invitations to new backoffice users from the Umbraco backoffice. Attempting to resolve this by manually adding third-party SMTP server settings (such as SendGrid) results in unhandled controller exceptions or protocol violations during the invitation request. Conversely, if manual SMTP settings are entirely missing or removed, the error logs disappear, but the invitation emails still fail to arrive in the invitees' mailboxes.

Solution:

To address backoffice user invitation issues on Umbraco Cloud across all versions, follow these troubleshooting and remediation steps:

1. Identify and Remove Conflicting SMTP Settings

Because Umbraco Cloud handles user invitations automatically via an internal platform fallback, manual SMTP settings are completely unnecessary for invitations and can cause network or protocol conflicts.

  • For Umbraco 8 and below: Open your project's web.config file, locate the <system.net>/<mailSettings> block, and remove or comment out the manual <smtp> configuration.

  • For Umbraco 9 and above: Check your appsettings.json or environment-specific settings for the Umbraco:CMS:Global:Smtp configuration block.


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    Note: Manual SMTP settings are only required if you need to support other application email features, such as password resets or Umbraco Forms workflows. If you must keep them for these features, apply them cleanly via environment transforms or Cloud Portal environment variables.

2. Utilize the Cloud Portal Workaround

If the backoffice application layer continues to experience delivery or execution failures, you can bypass the CMS entirely by issuing the invitation through the infrastructure platform:

  • Log into the Umbraco Cloud Portal.

  • Navigate to your project page $\rightarrow$ Overview $\rightarrow$ Team.

  • Send or resend the invitation to the user directly from this interface. This successfully provisions the backoffice user profile cleanly from the portal layer.

3. Verify Delivery and Spam Status

If no runtime errors appear in the logs but emails are still not arriving, the issue points to external email delivery and filtering rather than a site configuration problem:

  • Check the recipient's spam, junk, or corporate quarantine folders.

  • Verify that the invitation has not already been completed by the user.

  • Review your health checks or dashboard logs to ensure your system's notification email settings are changed from default placeholders (like your@email.here) to a valid domain email address to prevent outbound email suppression.

Article last update date: 18-05-2026

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