Sending Multiple Emails in ASP.NET Using Gmail Account

Introduction:

In a previous article, we explored the process of sending emails in ASP.NET using a Gmail account. Building on that knowledge, this tutorial focuses on a more advanced aspect – sending multiple emails at once using C# coding. Additionally, we'll touch upon resolving the SMTP server's secure connection and authentication errors.

HTML Markup for Bulk Email Sending Page:

To begin, let's create an HTML markup for the bulk email sending page. The page includes input fields for the recipient's email addresses and the email message.

  <div>
      <table>
      <tr>
      <td colspan="3" style="width:50px;">
      </td>
      <td>
        <table>
      <tr>
       <th colspan="2" align="left">Multiple Mail Sending</th>
      </tr>
      <tr>
      <td style="width:20px;">To : </td><td><asp:TextBox ID="txt_mul_mail" runat="server" Width="310px"></asp:TextBox></td>
      </tr>
      <tr>
      <td colspan="2">
       <asp:TextBox ID="txt_mul_msg" runat="server" TextMode="MultiLine" Width="336px" 
              Height="199px"></asp:TextBox>
      </td>
      </tr>
      <tr>
       <td colspan="2">
        <asp:Button ID="Btn_mul_mail" runat="server" Text="Send Multiple Mail" 
               onclick="Btn_mul_mail_Click" />
       </td>
      </tr>
     </table>
      </td>
      </tr>
     </table>
    </div>

C# Coding for Sending Multiple Emails:

Now, let's delve into the C# coding to handle the logic for sending multiple emails. The code extracts the recipient email addresses, constructs the email message, and utilizes the SMTPClient class for sending.

protected void Btn_mul_mail_Click(object sender, EventArgs e)
    {
        string to_email_id = txt_mul_mail.Text;
        MailMessage ms = new MailMessage();
        ms.From = new MailAddress("Your Gmail ID");
        ms.Subject = "Testing Sending Multiple Mail at a Time";
        ms.Body = txt_mul_msg.Text;
        string[] multiple_to_sending_mail = to_email_id.Split(',');
        foreach (string to_multiple_email in multiple_to_sending_mail)
        {
            ms.To.Add(to_multiple_email);
        }
        ms.IsBodyHtml = true;
        SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587);
        smtp.Credentials = new System.Net.NetworkCredential("Your Gmail ID", "Your Gmail ID Password");
        smtp.EnableSsl = true;
        smtp.Send(ms);
    }

Conclusion and Next Steps:

In this tutorial, we learned how to send multiple emails in ASP.NET using a Gmail account. We utilized the MailMessage and SMTPClient classes from the System.Net.Mail namespace for effective email communication. As a next step, consider exploring how to resolve SMTPException errors that may arise during the email sending process.

Next Tutorials: How to Resove SMTPException

By following these tutorials, you'll enhance your skills in email communication within ASP.NET applications.