How to Resolve Common Send Failures

If your test email fails to send, ContactMonkey emails you an alert with a specific error message. This article explains what each error means and the steps to resolve it so you can get back to testing your emails.

How do I fix the "404 Not Found: Draft not found" error?

This error means ContactMonkey can't find the draft of your email in your Outlook Drafts folder. It usually happens when the Microsoft account you're signed in to doesn't match the email address licensed with ContactMonkey, or when you're sending from a shared mailbox that isn't set up correctly.

Problem: ContactMonkey can't locate your email draft in the mailbox you're sending from.

Solution: Confirm the account you're signed in to matches your ContactMonkey license, then reset your connection.

1. Open the ContactMonkey Add-in in Outlook and click the gear icon
2. Compare the email address shown in the sidebar with the email address on your ContactMonkey license. If they don't match, click Log Out, then sign back in with the correct Microsoft account.
3. If you're sending from a shared mailbox, confirm you are following the steps in this article

Note: If you use Outlook for Mac and the error persists after these steps, contact your IT team and ask them to update the shared mailbox's UPN to match its email address exactly.

How do I fix the "Could not authenticate with Outlook" error?

This error means your ContactMonkey connection to Outlook has expired or broken — often after a password change or a period of inactivity. Resetting your Outlook token resolves it in most cases.

Problem: ContactMonkey can no longer authenticate with your Outlook account.

Solution: Reset your Outlook token to reconnect your account.

Reach out to support@contactmonkey.com to request a manual token refresh. If the issue persists, ask a ContactMonkey Admin to navigate to Settings → Integrations and reconnect to the Graph Utility Account tile by signing out and back in.

How do I fix the "You do not have permission to 'Send As' the selected mailbox" error?

This error means the address in your From field requires Send As permission that your account doesn't have.

Problem: You don't have Microsoft permission to send from the selected mailbox.

Solution: Ask your IT team or Exchange administrator to grant you Send As permission on that mailbox.

1. Confirm which address is in the From field of your test email
2. Contact your IT team or Exchange administrator and request Send As permission for that mailbox. ContactMonkey can't grant Microsoft mailbox permissions on your behalf.
3. To check that the permission works, send a regular (non-ContactMonkey) email from that mailbox using Outlook's native Send button. If it sends successfully, retry your test email in ContactMonkey.

Important: If your organization uses Email at Scale, your ContactMonkey Send As Permissions apply to full campaign sends with Individual or Anonymous tracking — not to Send Test. Click here to manage these permissions.

How do I fix the "There was an unhandled error" message?

This error means something unexpected interrupted your send. Retrying after refreshing your connection resolves most cases.

Problem: An unexpected error stopped your test email from sending.

Solution: Refresh your ContactMonkey connection and try the test send again.

1. Close and reopen the ContactMonkey Add-in in Outlook, then retry your send
2. If the error repeats, log out of the sidebar with the gear icon and sign back in
3. If the error still appears, contact our support team at support@contactmonkey.com with the date and time of the failure and the email template you were testing, so our team can investigate