SendGrid not working from Azure App Service

Question

I am using the latest SendGrid .NET package (8.0.3) to send e-mails from my ASP.NET Core web app:

public Task SendEmailAsync(string email, string subject, string message)
{
    return Send(email, subject, message);

}

async Task Send(string email, string subject, string message)
{
    dynamic sg = new SendGridAPIClient(_apiKey);

    var from = new Email("[email protected]", "My Name");
    var to = new Email(email);
    var content = new Content("text/html", message);
    var mail = new Mail(from, subject, to, content);

    await sg.client.mail.send.post(requestBody: mail.Get());
}

It works locally, but running on an Azure App Service instance the mails don't come through.

The code runs fine without any exceptions so I have little to work with, but I am thinking it could be some sort of firewall issue.

Has anyone experienced similar issues? How do I go about to debug this?

Answer 1

Although the question is old I'm providing an answer as I came across a similar issue and couldn't find any clear solutions. The reason why it wasn't working for me was because

• I hadn't referenced Microsoft.Azure.WebJobs.Extensions.SendGrid. The solution to this is to add it from Nuget

• I wasn't waiting for the async send to complete. Add .Wait() to the async function that sends the email. The full code I used for program.cs is below:

  static void Main()
  {
      var config = new JobHostConfiguration();
  
      if (config.IsDevelopment)
      {
          config.UseDevelopmentSettings();
      }
      config.UseSendGrid();
  
  //The function below has to wait in order for the email to be sent
      SendEmail(*Your SendGrid API key*).Wait();
  
  
  }
  
  public static async Task SendEmail(string key)
  {
  
      dynamic sg = new SendGridAPIClient(key);
  
      Email from = new Email("[email protected]");
      string subject = "Test";
      Email to = new Email("[email protected]");
  
      Content content = new Content("text/html", "CONTENT HERE");
      Mail mail = new Mail(from, subject, to, content);
  
  
  
      dynamic s = await sg.client.mail.send.post(requestBody: mail.Get());
  
  }
  

So I would suggest you add .Wait() to your function call:

public Task SendEmailAsync(string email, string subject, string message)
{
    //Added .Wait()
    return Send(email, subject, message).Wait();
}