Sending email using EWS and OAuth2

GemBox.Email
1

Hi

I have installed the latest version of GemBox.Email (15.0.1039) and trying to send e-mail using this example.

var exchClient = new ExchangeClient("https://outlook.office365.com/EWS/Exchange.asmx");
exchClient.Authenticate("from@address.no", myAccessToken, ExchangeAuthentication.OAuth2);

var message = new MailMessage(
    new MailAddress("from@adddress.no", "From name"),
    new MailAddress("to@address.no", "Recipient Name"))
{
    Subject = "Send Email in C#",
    BodyText = "Hi,\n" +
        "This message was created and sent with GemBox.Email.\n" +
        "Read more about it on gemboxsoftware"
};

exchClient.SendMessage(message);

The exchClient.SendMessage code fails with the error:
The remote server returned an error: (500) Internal Server Error.

To verify that my access token is correct and I can send email successfully, I used the same token to successfully send an email using Exchange.WebServices.Managed.Api:

var ewsClient = new ExchangeService();
ewsClient.Url = new Uri("https://outlook.office365.com/EWS/Exchange.asmx");
ewsClient.Credentials = new OAuthCredentials(myAccessToken);
ewsClient.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, "from@address.no");

var message = new EmailMessage(ewsClient)
{
    Subject = "This is a test", 
    Body = new MessageBody(BodyType.HTML, "This is a test body"), 
    From = new EmailAddress("from@address.no")
};

message.ToRecipients.Add("to@address.no");
message.Send();

Is there a bug in GemBox.Email library for EWS that result in the 500 internal server error?

Thank you

Regards
Arild

2

Hi Arild,

Can you try running again that code of yours that uses Exchange.WebServices.Managed.Api, but remove this line:

ewsClient.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, "from@address.no");

Does it reproduce the same issue?
I presume the problem is with the permissions and the above should result in an Exception as well.

Unfortunately, GemBox.Email currently doesn’t support impersonating a user (mailbox).
Also, I’m afraid that at the moment I cannot say when exactly this will be available.

If interested, please feel free to create a GemBox.Email feature request for this so that other users may vote for it, thus increasing its priority.

Regards,
Mario

3

Hi Mario

Thank you for your reply.

I have tried removing the ImpersonateUserId line and the result was an error:
“ExchangeImpersonation SOAP header must be present for this type of OAuth token.”

So if I understand you correctly I need to make sure permissions allow me to use the mailbox “directly”, without any impersonation. Then GemBox Email should work as expecte.

Regards
Arild

4

Yes, exactly!

Regards,
Mario