从服务帐户使用 Graph API 发送电子邮件

我正在 ASP.NET Core 5 (C#) 中执行任务，需要使用 Graph API 发送电子邮件，我参考了以下文章并在 Azure 试用帐户上进行了配置，并且能够发送电子邮件。

使用 .NET 通过 Microsoft Graph 发送电子邮件 https://zimmergren.net/sending-e-mails-using-microsoft-graph-using-dotnet/

这是发送电子邮件的代码：

//send email
var client = await GetAuthenticatedGraphClient();
    
await client.Users[senderObjectId]
                  .SendMail(graphMailMessage, true)
                  .Request()
                  .PostAsync();

senderObjectId- 来自配置的对象 ID

我们在客户端的 Azure 帐户上部署了相同的代码，我们需要服务帐户的用户对象 ID，并将其用作发件人的电子邮件 ID。然而，客户回来说该帐户不是 Azure AD 的一部分，而是一个服务帐户。有没有一种方法可以在不使用用户对象 ID 的情况下发送电子邮件。

这是采用邮件发送参数的方法。此外，它还分隔了 (comma) 邮件并将其发送给多个用户

    public string SendEmail(string fromAddress, string toAddress, string CcAddress, string subject, string message, string tenanatID , string clientID , string clientSecret)
    {
            try
            {

                var credentials = new ClientSecretCredential(
                                    tenanatID, clientID, clientSecret,
                                new TokenCredentialOptions { AuthorityHost = AzureAuthorityHosts.AzurePublicCloud });
                GraphServiceClient graphServiceClient = new GraphServiceClient(credentials);


                string[] toMail = toAddress.Split(',');
                List<Recipient> toRecipients = new List<Recipient>();
                int i = 0;
                for (i = 0; i < toMail.Count(); i++)
                {
                    Recipient toRecipient = new Recipient();
                    EmailAddress toEmailAddress = new EmailAddress();

                    toEmailAddress.Address = toMail[i];
                    toRecipient.EmailAddress = toEmailAddress;
                    toRecipients.Add(toRecipient);
                }

                List<Recipient> ccRecipients = new List<Recipient>();
                if (!string.IsNullOrEmpty(CcAddress))
                {
                    string[] ccMail = CcAddress.Split(',');
                    int j = 0;
                    for (j = 0; j < ccMail.Count(); j++)
                    {
                        Recipient ccRecipient = new Recipient();
                        EmailAddress ccEmailAddress = new EmailAddress();

                        ccEmailAddress.Address = ccMail[j];
                        ccRecipient.EmailAddress = ccEmailAddress;
                        ccRecipients.Add(ccRecipient);
                    }
                }
                var mailMessage = new Message
                {
                    Subject = subject,

                    Body = new ItemBody
                    {
                        ContentType = BodyType.Html,
                        Content = message
                    },
                    ToRecipients = toRecipients,
                    CcRecipients = ccRecipients

                };
                // Send mail as the given user. 
                graphServiceClient
                   .Users[fromAddress]
                    .SendMail(mailMessage, true)
                    .Request()
                    .PostAsync().Wait();

                return "Email successfully sent.";

            }
            catch (Exception ex)
            {

                return "Send Email Failed.\r\n" + ex.Message;
            }
    }