Using SendGrid: A Guide to Simplifying Email Communication

In today’s digital landscape, email remains one of the most effective ways to communicate with customers, clients, and users. Whether you're running an e-commerce site, managing a SaaS product, or sending newsletters, email marketing, and transactional emails are essential parts of business operations. For many organizations, SendGrid provides a reliable and scalable solution to handle email sending and tracking.

What is SendGrid?

SendGrid is a cloud-based email delivery service designed to help businesses send email campaigns, transactional emails, and notifications at scale. It offers robust features that allow developers, marketers, and organizations to streamline their email workflows. From simple emails to complex marketing campaigns, SendGrid simplifies the technical complexities of email sending and ensures high deliverability.

Sending Emails with SendGrid in .NET Core

Step 1: Create a SendGrid Account

Before using SendGrid in your .NET Core application, you'll need a SendGrid account. Follow these steps:

1. Sign up at SendGrid.
2. After logging in, navigate to Settings > API Keys.
3. Click Create API Key, choose Full Access, and copy the generated API key.

Step 2: Install the SendGrid NuGet Package

Install the SendGrid NuGet package in your project via the NuGet Package Manager or by running the following command in the terminal:

dotnet add package SendGrid        

This will add the necessary libraries for interacting with the SendGrid API.

Step 3: Store SendGrid API Key in appsettings.json

To securely store your SendGrid API Key, place it in your appsettings.json file:

{
  "SendGrid": {
    "ApiKey": "your_sendgrid_api_key_here"
  }
}        

Step 4: Configure SendGrid in Startup.cs

In Startup.cs, register your SendGrid settings and the service that will handle sending emails.

public class Startup
{
    public IConfiguration Configuration { get; }

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        // Bind SendGrid settings
        services.Configure<SendGridSettings>(Configuration.GetSection("SendGrid"));

        // Register SendGrid service
        services.AddTransient<ISendGridService, SendGridService>();

        services.AddControllersWithViews();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseRouting();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");
        });
    }
}        

Step 5: Create the SendGridSettings Class

Define a class to hold your SendGrid settings:

public class SendGridSettings
{
    public string ApiKey { get; set; }
}        

Step 6: Create a SendGrid Service

Now, create a service that handles email sending using SendGrid:

using SendGrid;
using SendGrid.Helpers.Mail;
using Microsoft.Extensions.Options;
using System.Threading.Tasks;

public interface ISendGridService
{
    Task SendEmailAsync(string toEmail, string subject, string plainTextContent, string htmlContent);
}

public class SendGridService : ISendGridService
{
    private readonly SendGridSettings _settings;

    public SendGridService(IOptions<SendGridSettings> settings)
    {
        _settings = settings.Value;
    }

    public async Task SendEmailAsync(string toEmail, string subject, string plainTextContent, string htmlContent)
    {
        var client = new SendGridClient(_settings.ApiKey);
        var from = new EmailAddress("[email protected]", "Your Company");
        var to = new EmailAddress(toEmail);
        var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);

        try
        {
            var response = await client.SendEmailAsync(msg);
            Console.WriteLine($"Email sent with status code: {response.StatusCode}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error sending email: {ex.Message}");
        }
    }
}        

Step 7: Create an Email Controller

Now, create a controller to trigger the email-sending function. Here’s an example:

using Microsoft.AspNetCore.Mvc;
using System.Threading.Tasks;

public class EmailController : Controller
{
    private readonly ISendGridService _sendGridService;

    public EmailController(ISendGridService sendGridService)
    {
        _sendGridService = sendGridService;
    }

    [HttpPost]
    public async Task<IActionResult> SendEmail()
    {
        string toEmail = "[email protected]";
        string subject = "Test Email from SendGrid";
        string plainTextContent = "This is a plain text email.";
        string htmlContent = "<strong>This is an HTML email.</strong>";

        await _sendGridService.SendEmailAsync(toEmail, subject, plainTextContent, htmlContent);
        return Ok("Email Sent Successfully");
    }
}        

Step 8: Testing the Email Endpoint

Run the application and navigate to the /email/sendemail endpoint (or whichever route you defined). This will trigger the email to be sent to the specified recipient.

Step 9: Handle Errors and Responses

The SendGridService includes error handling to catch any exceptions thrown during the email-sending process. You can further refine this by customizing error messages or logging the responses for debugging purposes.

Step 10: Optional - Using SendGrid Templates

If you prefer using SendGrid’s email templates instead of manually creating HTML emails, you can set up a template in your SendGrid dashboard. Once created, you can reference it when sending emails:

var msg = new SendGridMessage
{
    From = new EmailAddress("[email protected]", "Your Name"),
    Subject = subject,
    HtmlContent = htmlContent,
    PlainTextContent = plainTextContent
};
msg.AddTo(new EmailAddress(toEmail));

// Set template ID
msg.SetTemplateId("your_template_id");

var response = await client.SendEmailAsync(msg);        

Conclusion

Integrating SendGrid with a .NET Core application is straightforward. By following these steps, you can easily send emails, whether they are transactional or marketing-related. SendGrid’s API and .NET SDK provide powerful tools for ensuring email deliverability and efficient email sending at scale.