I need to send mails from a background application(worker service/azure function) using MSGraph API with Application permission. This is how I have initialized the GraphServiceClient to send emails.
var credentials = new ClientSecretCredential(
"TenantID",
"ClientId",
"ClientSecret",
new TokenCredentialOptions { AuthorityHost = AzureAuthorityHosts.AzurePublicCloud });
GraphServiceClient graphServiceClient = new GraphServiceClient(credentials);
var subject = $"Subject from demo code";
var body = $"Body from demo code";
// Define a simple e-mail message.
var email = new Microsoft.Graph.Message
{
Subject = subject,
Body = new ItemBody
{
ContentType = BodyType.Html,
Content = body
},
ToRecipients = new List<Recipient>()
{
new Recipient { EmailAddress = new EmailAddress { Address = "EmailId" }}
}
};
// Send mail as the given user.
graphServiceClient
.Users["UserID"]
.SendMail(email, true)
.Request()
.PostAsync().Wait();
How long the graphServiceClient will have a valid token and how to regenerate a token when the token is expired.
What are the best practices for this usage
As of May 2022, there is no option to generate a refresh token while using client_credentials options.
It's possible to generate a refresh token while using on behalf of user