My windows daemon successfully sends emails via the graph API (code below). However, xxx.williams@outlook.com does not receive them. Why not? I, xxx.williams@outlook.com, have an active MS 365 Apps for Business license and am the admin. sendMail has application permissions along with all other mail and mailbox permissions. xxx.williams@outlook.com junk mail folder is empty returns: ============ SEND MAIL ================= OK {"@odata.context":"https://graph.microsoft.com/v1.0/$metadata#users/$entity","businessPhones":["7815073118"],"displayName":"XXXWilliams","givenName":"XXX","jobTitle":null,"mail":null,"mobilePhone":null,"officeLocation":null,"preferredLanguage":"en","surname":"Williams","userPrincipalName":"XXxxWilliams@Xxx.onmicrosoft.com","id":"xxxxxxxx-58c0-42a6-9203-06eec6882b5c"} What is broken?

Your graphapi call is getting the user profile, not sending an email message. Also no content is sent with the get method, only headers. from the response display it seems to be working correctly. To send mail see https://learn.microsoft.com/en-us/graph/api/user-sendmail?view=graph-rest-1.0&tabs=http

Recipient does not Receive Emails Successfully Sent via Graph API sendMail. Why not?

Accepted answer

Bruce (SqlWork.com) 69,976 Reputation points

2025-01-26T02:00:43.57+00:00

Your graphapi call is getting the user profile, not sending an email message. Also no content is sent with the get method, only headers.

from the response display it seems to be working correctly. To send mail see

https://learn.microsoft.com/en-us/graph/api/user-sendmail?view=graph-rest-1.0&tabs=http
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We s 20 Reputation points

2025-01-26T04:55:37.3233333+00:00

oh NO! I am so sorry to have made such a bonehead mistake. I was troubleshooting and I took out the sendmail and forgot to put it back in. I will accept the answer and repost tomorrow but here is the corrected version if someone else has the answer I'm looking for. This has the POST and the /users/{userId}/sendmail endpoint. (not /me/ since that returns "bad request")

============ SEND MAIL =================

NotFound

{"error":{"code":"MailboxNotEnabledForRESTAPI","message":"The mailbox is either inactive, soft-deleted, or is hosted on-premise."}}

Why the "mailbox not enabled"? It is all enabled as far as I know.

Thanks

Jake Zhang-MSFT 8,400 Reputation points Microsoft Vendor

2025-01-27T09:19:26.11+00:00

The error message "MailboxNotEnabledForRESTAPI" typically indicates that the mailbox is either inactive, soft-deleted, or hosted on-premise.

Here are a few things you can check:

Ensure that the mailbox is active and not soft-deleted. You can verify this in the Microsoft 365 admin center under the user's mailbox settings.

Confirm that the mailbox is hosted in Exchange Online and not on-premise. The Graph API requires the mailbox to be in Exchange Online.

Double-check that the user has the appropriate Microsoft 365 license assigned, which includes Exchange Online.

Verify that the application has the necessary permissions to access the mailbox. Ensure that the Mail.Send permission is granted and consented properly.

If the user is a guest user from another tenant, they might not have a mailbox in your tenant. Guest users typically have mailboxes in their home tenant.
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Recipient does not Receive Emails Successfully Sent via Graph API sendMail. Why not?

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