How can I access mails from Shared mailbox using Mailkit - oauth-2.0

Recently Microsoft has started to authenticate user with OAuth 2.0 protocol. I have implemented it in Asp.net Core C# and got token.
Now I am able to access mails from main mail Inbox using Mailkit from Microsoft exchange server using OAuth 2.0. But how can I be able to access mails from shared mailbox?
In my code I have mentioned shared mailbox account id.
My code is as follows
Code
Getting exception as "Autheticated but not connected". Please guide

The "Authenticated but not connected" error is unique to Microsoft Exchange IMAP servers and means that your account is not authorized to connect via IMAP.
You will need to be granted permissions for IMAP access by the admin of your tenant.

Need to give shared mailbox permissions to OAuth app as well and shared mailbox will be accessible.

Related

How to configure an app in azure portal for multiple email addresses, from the same O365 tenant, to use OAuth with SMTP without user interaction?

We use in our company email addresses for each employee and for 3 departments (service, support and reports) - for example <employee_name>#<company_name>.de or support#<company_name>.de ("<..._name>" is just a placholder for posting here). Our programs use PHPMailer for sending Emails from the 3 departments via SMTP without user interaction (Host: smtp.office365.com), that means the PHPMailer is called by programs/scripts that are started by the Microsoft Task Scheduler on a computer where none of our Microsoft-Users is logged in. Now we want to switch from Basic SMTP Auth to Oauth2.
So we registered in the main tenant (<boss_name>#<company_name>.de) in the azure portal a web app "PHPMailer" and received the refresh token with the file "get_oauth_token.php", which is included in PHPMailer. The mail order via OAuth is working now, but only when <boss_name>#<company_name>.de is the username and the email sender (From).
It's not working when both are for example reports#<company_name>.de (prefered way)
SMTP INBOUND: "535 5.7.3 Authentication unsuccessful [AM6PR10CA0036.EURPRD10.PROD.OUTLOOK.COM]"
And it's not working when <boss_name>#<company_name>.de is the username and From is for example reports#<company_name>.de (willy-nilly compromise)
SMTP INBOUND: "554 5.2.252 SendAsDenied; <boss_name>#<company_name>.de not allowed to send as reports#<company_name>.de
We tried to change the configuration for <boss_name>#<company_name>.de ("SendAs" parameter) and of the app in the azure portal (for example defining the department email addresses as owner of the app or adding Mail.Send in the Micrsoft Graph API as application permission) and waited 24 hours (synchronization delay) - but no change.
So i've read in the past weeks countless tutorials from Microsoft, PHPMailer and others, and forums like stackoverflow. But nowhere i could find the necessary information, how to change the configuration.
Examples:
Microsoft
Give mailbox permissions to another Microsoft 365 user - Admin help
Authenticate an IMAP, POP or SMTP connection using OAuth
Get access on behalf of a user
PHPMailer
Using Gmail with XOAUTH2 (unfortunately no explanation for Microsoft)
Basic Usage of the OAuth 2.0 Client from the PHP League
Microsoft Provider for OAuth 2.0 Client Microsoft OAuth 2.0 support for PHPMailer from Steven Maguire
But in this answer to my older question #ADyson wrote that the app just needs the appropriate permissions in the Graph API - so it must be possible. Unfortunately he didn't write, how to set the permissions...
So, how can i achieve my goal?
(Because the PHPMailer is working and i think it's just a configuration problem, i omitted code snippets. If you although need code or more information, please tell me...)
Update:
PHPMailer
Thanks to #greew i found a well made explanation with helpfull screenshots for delegated permissions:
Microsoft Azure and XOAUTH2 setup guide
Unfortunately it doesn't help for my case with application permissions, because it is made for the case, that the Microsoft user is logged in on the compauter where PHPMailer is working.
Not supported?
I found in the Microsoft page Authenticate an IMAP, POP or SMTP connection using OAuth the following hint:
Note As per the current test with SMTP Oauth 2.0 client credential flow with non-interactive sign in is not supported.
Does this mean, that i'm trying it for nothing, because it is not supported???
#biberman
I just tried setting up a new mailer with the correct permissions and also clicking the "Grant admin consent.." button.
This resulted in me being able to both get the refresh token and also send mail without user interaction on my behalf.
Note: I'm using the single tenant option in the App.
After i found in the Microsoft page Authenticate an IMAP, POP or SMTP connection using OAuth the following hint:
Note As per the current test with SMTP Oauth 2.0 client credential flow with non-interactive sign in is not supported.
i asked the same question in the Microsoft Q&A forum. There i received the following answer/comment:
Currently the Client Credentials flow isn't supported with SMTP Auth (it maybe in the future but there isn't a roadmap item that i know of) so you need to grant SendAS permissions to whatever account you trying to send as in the from or switch to using the Graph API eg one example https://katystech.blog/projects/php-graph-mailer that does support the client credentials flow.
I tried to solve the issue by letting the administrator grant the SendAs permission to all necessary mailboxes, but i still get the error SendAsDenied - maybe it doesn't work with modern authentication (OAuth).
At the end i used the graphMailer from the linked katystech.blog, which is a really slim solution compared to the PHPMailer. First i couldn't get it to work, because our administrator refused to grant the necessary Microsoft Graph permission Mail.ReadWrite (he has security concerns). But i changed the code, so that the email is "build" before sending it, instead of building the email step by step on the Microsoft server and then advising the server to send it (like in the original code).
Now the Mail.ReadWrite permission isn't necessary and i can send from different email addresses. To avoid rewriting the whole code, where the PHPMailer is used, i renamed the functions of Katys graphMailer (and adjusted the params), so that they are similar to the PHPMailer and i only need to replace = new PHPMailer( with = new graphMailer(...

Sending Email using Azure EWS with OAuth2.0 Client Credential

I have question 'bout using EWS with Oauth2.0 Client Credential.
In our directory, there're users with member type and guest type, however, all of our administrators are from Microsoft directory(using v-xxx#microsoft.com) and they are under guest.
My question is if it's possible to use credential client grant type, and use EWS to send email behalf of these guest users?
For now, I tried to use EASendMail sdk to achieve this task. However, whenever I use account within our directory(member type) I get "There is no SMTP email associated" which is what I expected, 'cause we do not have email address associated with these users. But when I tried using (v-xxx#microsoft.com) , "Mailbox does not exist" error is raised.
Thank you.
You can do as long as the app has been granted impersonation permissions. OAuth is supported for the client credential flow(app permissions) & impersonation to do so.

Azure AD App-only token to consume outlook REST API

I am developing a console app in .net which will send mail using the Azure AD application. I followed all the step from generating the certificates to registered an application in Azure AD. Then provided the application permission (Send mail as any user) using Microsoft graph API and provided it “grant permission” as an admin consent.
In my console app code I uses the below outlook api to send mail as
resourseurl — https://outlook.office.com/api/v1.0/users/{my email account}/sendmail. After providing grant permission to my app I am still facing the 401:unauthorized error.
You gave permissions to Microsoft Graph API, so you need to use it.
https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/api/user_sendmail
The URL that you need to use is thus:
POST https://graph.microsoft.com/v1.0/users/{id | userPrincipalName}/sendMail
Internally the graph API does call the API you mentioned. But your token is for the graph. Not the outlook API.
You also mentioned the resource URL. The graph API resource URL is https://graph.microsoft.com.

Utilizing OAuth2 for Office365, through Exchange ActiveSync (EAS)

The blog post: Announcing Exchange ActiveSync v16.1 states that:
While not a part of EAS 16.1, we also want to note that both Office 365 and Outlook.com customers can now utilize the OAuth 2.0 protocol for authorization through EAS.
My question is: which scope should I use in the oauth request?
Is there an example, perhaps of the full request?
Note: there was a similar question about using OAuth for Office365 with IMAP, but here I'm specifically asking about ActiveSync. I referenced this question in a comment to one of the answers on that thread.
Secondary problem:
Thanks to Jason's answer and some additional tweaks, we managed to generate oauth token using https://login.windows.net/common/oauth2 but only for office365 users (Organization Accounts) and not to Microsoft users account (live, hotmail, outlook.com...)
The token allows access to both ActiveSync protocol (via https://eas.outlook.com/Microsoft-Server-ActiveSync) and for EWS API (via https://outlook.office365.com/EWS/Exchange.asmx).
Unfortunately we cannot find a way to generate same token for Microsoft online accounts (hotmail, live, outlook.com). We tried using this endpoint: https://login.live.com/oauth20_authorize.srf which allow only activesync and not EWS.
Is there a way to use the same token for both organization and online accounts on both protocols (ActiveSync and EWS)?
Sorry this took so long, but I wasn't aware of this question until today :). You need to register your app as a native application in Azure Active Directory:
Then add the Access mailboxes as the signed-in user via Exchange Web Services (under Office 365 Exchange Online) delegated permission.
NOTE: You cannot register this in the Application Registration Portal (https://apps.dev.microsoft.com), it needs to be registered in the Azure Portal (https://portal.azure.com/), and you need to use the v1 Azure auth endpoints for authorization and token requests.

Microsoft Graph API .NET not able to read shared mail

First post...here goes. I am trying to display email from a shared mailbox but run into "ErrorAccessDenied Access is denied. Check credentials and try again".
The user does have permission to the mailbox, I can access/read email in Outlook and in O365 portal. In my app I have also assigned Mail.Read.Shared and Mail.ReadWrite.Shared scopes.
At first I tried Graph Explorer
https://graph.microsoft.com/beta/users/<userPrincipalNameOfSharedMailbox>/messages
but same ErrorAccessDenied, assumed Graph Explorer did not have Mail.Read.Shared scope.
Next I tried to modify Microsoft Graph Snippets Sample for ASP.NET 4.6
I added Mail.Read.Shared and Mail.ReadWrite.Shared and was prompted to accept these permissions
• Read and write mail you can access
• Read mail you can access
but I get the same error when I try get mail from the shared mailbox
IUserMessagesCollectionPage messages = await graphClient.Users["userPrincipalNameOfSharedMailbox"].Messages.Request().GetAsync();
There was a similar post here Microsoft Graph API SDK .NET Issues getting other users emails and the answer implies this is possible. If it is can anyone provide some insight as to what I am missing? thanks
Right now, accessing shared messages is not supported for the authorization_code flow, but it is supported for the client_credentials flow. In order to incorporate this functionality, you will have to change your flow to incorporate this.
Here is an article on creating a client_credentials flow app if you are interested in going this route.

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