SendGrid 将类别添加到邮件

Question

我正在使用 SendGrid，我想在电子邮件中添加一个或多个类别，但添加的类别尚未发送！

这是代码：

internal class Example
{
    private static void Main()
    {
        Execute().Wait();
    }

    static async Task Execute()
    {
        //FYI, the following three variables are not real
        var apiKey = "SG.XXX";
        var fromEmail = "";
        var toEmail = "";

        var client = new SendGridClient(apiKey);
        var from = new EmailAddress(fromEmail);
        var subject = "Sending with SendGrid is Fun";
        var to = new EmailAddress(toEmail);
        var plainTextContent = "and easy to do anywhere, even with C#";
        var htmlContent = "<strong>and easy to do anywhere, even with C#</strong>";
        var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);
        msg.AddHeader("category", "cat1"); //This line does nothing!
        var response = await client.SendEmailAsync(msg);
    }
}

Answer 1

谢谢Kami，我试过你的回答，效果很好。

我将这一行 msg.AddHeader("category", "cat1"); 替换为 msg.AddCategory("cat1");