I am trying to send email from my MVC application, it sends fine when I use the .Send() method but takes a while to come back so I wanted to use the .SendMailAsync() function, but I am receiving the following error during execution.
An asynchronous operation cannot be started at this time. Asynchronous operations may only be started within an asynchronous handler or module or during certain events in the Page lifecycle. If this exception occurred while executing a Page, ensure that the Page is marked <%@ Page Async="true" %>
This is my code sample. How can I configure this to send using .SendMailAsync()
Email Wrapper Class:
using System.Net.Mail;
namespace Helpers
{
public class Email
{
// constants
private const string HtmlEmailHeader = "<html><head><title></title></head><body style='font-family:arial; font-size:14px;'>";
private const string HtmlEmailFooter = "</body></html>";
// properties
public List<string> To { get; set; }
public List<string> CC { get; set; }
public List<string> BCC { get; set; }
public string From { get; set; }
public string Subject { get; set; }
public string Body { get; set; }
// constructor
public Email()
{
To = new List<string>();
CC = new List<string>();
BCC = new List<string>();
}
// send
public void Send()
{
MailMessage message = new MailMessage();
foreach (var x in To)
{
message.To.Add(x);
}
foreach (var x in CC)
{
message.CC.Add(x);
}
foreach (var x in BCC)
{
message.Bcc.Add(x);
}
message.Subject = Subject;
message.Body = string.Concat(HtmlEmailHeader, Body, HtmlEmailFooter);
message.BodyEncoding = System.Text.Encoding.UTF8;
message.From = new MailAddress(From);
message.SubjectEncoding = System.Text.Encoding.UTF8;
message.IsBodyHtml = true;
SmtpClient client = new SmtpClient("relay.mail.server");
client.SendMailAsync(message);
}
}
}
Controller:
public ActionResult Index()
{
Email email = new Email();
email.To.Add("to@email.com");
email.From = "from@email.com";
email.Subject = "Subject";
email.Body = "<p><strong>Hello</strong></p><p>This is my first Email Message</p>";
email.Send();
}
EDIT
Further to the actual question asked, the underlying issue was the delay created when sending emails. I looked further into the actual issue and with the help of this post:
ASP.Net MVC background threads for email creation and sending
modified my Email Wrapper class to spawn off a new thread to perform the email processing:
using System.Net.Mail;
namespace Helpers
{
public class Email
{
// constants
private const string HtmlEmailHeader = "<html><head><title></title></head><body style='font-family:arial; font-size:14px;'>";
private const string HtmlEmailFooter = "</body></html>";
// properties
public List<string> To { get; set; }
public List<string> CC { get; set; }
public List<string> BCC { get; set; }
public string From { get; set; }
public string Subject { get; set; }
public string Body { get; set; }
// constructor
public Email()
{
To = new List<string>();
CC = new List<string>();
BCC = new List<string>();
}
// send
public void Send()
{
MailMessage message = new MailMessage();
foreach (var x in To)
{
message.To.Add(x);
}
foreach (var x in CC)
{
message.CC.Add(x);
}
foreach (var x in BCC)
{
message.Bcc.Add(x);
}
message.Subject = Subject;
message.Body = string.Concat(HtmlEmailHeader, Body, HtmlEmailFooter);
message.BodyEncoding = System.Text.Encoding.UTF8;
message.From = new MailAddress(From);
message.SubjectEncoding = System.Text.Encoding.UTF8;
message.IsBodyHtml = true;
SmtpClient client = new SmtpClient("relay.mail.server");
new Thread(() => { client.Send(message); }).Start();
}
}
}
