Send email via Microsoft Graph with personal account

Question

I have a small PHP application sending email to users (in my name).

I have a personal MS account and use outlook for emails.

As Microsoft does not support using basic auth to send email through SMTP, I started to look at how to implement OAuth to continue sending emails with my app.

It looks like I have to use MS graph, which I'm fine with, however I can't get it to work.

I registered my app within Entra/Azure AD and succeeded to send an email using graph explorer

If I try to do the same using either PHP (with or without MS SDK), either curl or postman I always get errors. I tried as an app or delegated.

The most recurring one is "The tenant for tenant guid '*****' does not exist" which it seems is because I don't have an office 365 account. I get it when using the tenant id in the authorize url "https://login.microsoftonline.com/{{TENANT}}/oauth2/v2.0/authorize".

I tried using common or consumers instead of my token id and in the first case I can not even login (account not found or similar error) and in the second case I get "unauthorized_client: The client does not exist or is not enabled for consumers"

How do I get a working access token to send an email?

Thanks in advance for any help

Answer 1

Hello SMSPGS,

Thank you for reaching out to Microsoft Support!

In response to your question, we tested it in postman, and it worked well, so here is our process for getting tokens:

1.Register multi-tenant application with account type as "Accounts in any organizational directory (Any Microsoft Entra ID tenant - Multitenant) and personal Microsoft accounts (e.g. Skype, Xbox)":

2.Make sure to enable public client option if you are using interactive flow for generating token:

3.Add the delegated permission Mail.Send and grant the administrator permission to:

4.Finally, do not use the /tenant-id endpoint to request the token when obtaining the token, as it only supports organizational logins, you should use the /common endpoint to log in to individual accounts.

GET https://login.microsoftonline.com/common/oauth2/v2.0/authorize
POST https://login.microsoftonline.com/common/oauth2/v2.0/token

Reference document:

https://learn.microsoft.com/en-us/graph/auth-v2-user?tabs=http

Hope this helps.

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