如何使用C#在SharePoint Online中向多个用户发送电子邮件

string siteUrl = "https://your-sharepoint-site-url";
string username = "your-username";
string password = "your-password";

using (ClientContext context = new ClientContext(siteUrl))
{
    context.Credentials = new SharePointOnlineCredentials(username, ConvertToSecureString(password));

    // 在这里编写发送电子邮件的代码
}

string emailSubject = "邮件主题";
string emailBody = "邮件内容";
string[] userEmails = { "user1@example.com", "user2@example.com" };

foreach (string userEmail in userEmails)
{
    EmailProperties emailProperties = new EmailProperties();
    emailProperties.Subject = emailSubject;
    emailProperties.Body = emailBody;
    emailProperties.To = new string[] { userEmail };

    Utility.SendEmail(context, emailProperties);
}