What's the Application "dev-rel-auth-prod" and why Status = "Failure" ?

[Kubilay67]

I've just started a O365 test account. With C# (code at the end below) I can successfully sign-in and can fetch folder names. No issues. However, the Sign-ins blade (https://portal.azure.com/#blade/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/SignIns) shows as Failure with below details.

Why it shows as a Failure?

Application

dev-rel-auth-prod

Status

Failure

Sign-in error code

500581

Failure reason

Other

Client app

Browser

My C# code.

var ewsClient = new ExchangeService();
ewsClient.Credentials = new WebCredentials("myemail@mydomain.onmicrosoft.com", "mypassword");
ewsClient.Url = new Uri("https://outlook.office365.com/EWS/Exchange.asmx");
var folders = ewsClient.FindFolders(WellKnownFolderName.MsgFolderRoot, new FolderView(100));
foreach (var folder in folders)
{
 Console.WriteLine ($"Folder: {folder.DisplayName}");
}

[#2]

Error 500581 = "Session information is not sufficient for single-sign-on on V2 with prompt=none to verify if MSA account."

So my guess is the client app says "Browser" but it is not really setting a cookie since it is PowerShell, so it is throwing an error that you can safely ignore.

BTW: Since EWS is considered a legacy authentication protocol, you should consider re-writing this code to authenticate with oAuth, otherwise when Microsoft blocks legacy authentication then your code will break. Originally they were going to block this in October 2020 but that deadline has been postponed due to COVID19.