Sendgrid-csharp: SendEmailAsync call in library not returning response when called from C# other project

[mhagesfeld]

Issue Summary

I have written a base library send call using SendGrid 9.0.12 and SendGrid C# HTTP 3.0 (see code below). This works when tests are run against it, or if I take it out of the library and run it directly from my web code. However, if I call it from my C# web code (see second code chunk below), the SendEmailAsync call never returns a result (though the email is sent). Any ideas?

Library Call

public async Task<string> SendEmail(string toAddresses, string fromEmailAddress, string fromName, string bccAddresses, string subject, string templateId, string bodyContent, Dictionary<string,string> substitutions)
{
 var message = new SendGridMessage();
            message.From = new EmailAddress(fromEmailAddress, name: string.IsNullOrEmpty(fromName) ? null : fromName);
            message.Subject = subject;
            if(!string.IsNullOrEmpty(templateId)) message.TemplateId = templateId;

            message.AddTos(GetEmailAddressListFromCommaSeparatedEmails(toAddresses));
            if(!string.IsNullOrEmpty(bccAddresses)) message.AddBccs(GetEmailAddressListFromCommaSeparatedEmails(bccAddresses));

            message.AddSubstitutions(substitutions);

            var client = new SendGridClient(apiKey);
            var response = await client.SendEmailAsync(message);
            return response.StatusCode.ToString();
}

C# Web Code

        public async Task<string> SendValidationEmail(string toAddress, string code, Guid invitationId)
{
var verificationUrl = string.Format("{0}/account/verify/{1}", ConfigurationManager.AppSettings["SiteUrl"], invitationId.ToString());
            var substitutions = new Dictionary<string, string>
            {
                { "-verificationurl-", verificationUrl},
            {"-code-", code }
        };
            var result = sender.SendEmail(
                toAddresses: toAddress,
                fromEmailAddress: ConfigurationManager.AppSettings["FromEmail"],
                fromName: ConfigurationManager.AppSettings["FromName"],
                subject: "Your Calfee Connect Verification Code",
              templateId: "94bae6c6-2d25-47b2-9198-21215e76d4a9",
              bccAddresses: string.Empty,
              bodyContent: string.Empty,
              substitutions: substitutions
              ).Result;
return result;
}

Steps to Reproduce

1. Set up project with SendEmail call
2. Test - works using separate test calls (NUnit Fixture)
3. Make MVC project with reference to project with SendEmail call
4. Call SendEmail - tracing, it does not get a response, though email is sent

Technical details:

• sendgrid-csharp Version: 3.0.0
• sendgrid versio: 9.0.12
• .NET Version: 4.5.2
• Visual Studio 2015
• Chrome

[mhagesfeld]

Making it a non-async call seems to have fixed it.

[thinkingserious]

Hello @mhagesfeld,

I was able to get it working with a very simple "ASP.NET Web Forms Project" targeting .NET 4.5.2.

I changed the code in Default.aspx.cs to:

using System;
using System.Web;
using System.Web.UI;
using SendGrid;
using SendGrid.Helpers.Mail;
using System.Threading.Tasks;

namespace TestingWebForms
{

    public partial class Default : System.Web.UI.Page
    {
        public void button1Clicked(object sender, EventArgs args)
        {
            var response = Execute();
            Response result = response.Result;
            button1.Text = result.Body.ReadAsStringAsync().Result;
        }

        public static async Task<Response> Execute()
        {
            var apiKey = Environment.GetEnvironmentVariable("SENDGRID_API_KEY");
            var client = new SendGridClient(apiKey);
            var from = new EmailAddress("[email protected]", "DX ");
            var subject = "Hello World from the SendGrid CSharp SDK!";
            var to = new EmailAddress("[email protected]", "Elmer Thomas");
            var plainTextContent = "Hello, Email!";
            var htmlContent = "<strong>Hello, Email!</strong>";
            var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);
            var response = await client.SendEmailAsync(msg);
            return response;
        }
    }
}

Upon success, the button will be empty (we don't return a body on successful mail/send call) and you will have received the email. If there was an issue, the button will contain the error.

[ray-winkelman]

I know this is closed. It's worth mentioning I had this issue and resolved it in the same way. Just straight up not responding isn't the expected behaviour of any .NET networking client. This should be fixed.