title: Unable to send multiple emails in BCCs using Sendgrid API for ASP.NET Core WebAPI
body: <p>I am working on a ASP.NET Core WebAPI where I am using SendGrid to send emails. Earlier, I was able to use the helper class CreateSingleEmail to send a single mail to a single recipient.
  Now, I wish to send the same email to multiple recipient in BCC so, the recipients are not able to see the other recipients.
  I have gone through many documentation on this issue and even the previous similar issues raised for this but I am still unable to send the mails.
  I have tried to use Personalization block too. I do not get any error per se but emails are not being sent through this.
  Here is my method-</p>
  
  <p>Please note that here, toEmail is of type List.</p>
  
  <pre><code>       var apiKey = "MySendgridApiKey"
          var client = new 
          SendGridClient(apiKey);
          var msg = new SendGridMessage();
          msg.SetFrom(new EmailAddress(fromEmail));
          msg.AddTo(new EmailAddress(fromEmail), 1);
          msg.SetBypassListManagement(true);
          msg.SetBccSetting(true, fromEmail);
          msg.AddSubstitution("%name1%", "Example User1");
          msg.SetSubject(subject);
          var personalization = new Personalization()
          {
              Bccs = toEmail  
          };
          msg.AddBccs(toEmail);
          msg.AddBccs(toEmail, 0, personalization);
          msg.Serialize();
          var response = client.SendEmailAsync(msg);
          return true;
  </code></pre>
  
  <p>Technical details:
  Platform ( ASP.NET Core WebAPI)
  .NET Core Version: 2.0.8</p>