In previous post, I have explained how to send email using Mailkit in ASP.NET Core. In this post, I will explain about how to send email using Gmail in ASP.NET.

The .NET framework has built-in namespace for handling email settings, which is System.Net.Mail namespace. In the following example, I’ll use two classes from the System.Net.Mail namespace:

  • For email settings, we will use the MailMessage class and
  • For smtp settings and sending email, we will use the SmtpClient class

I guess you are aware that mails are sent via an SMTP server, so we need to integrate smtp settings such as SMTP Host, Port, Credentials etc. If you don’t know about such things don’t worry, I’ll cover all these things in this tutorial.

What is SMTP?

SMTP stands for Simple Mail Transfer Protocol. It provides set of communication settings that allows our software or web applications to transmit or send emails over the internet with configured smtp settings.

Required Gmail SMTP Settings

Following are the list of SMTP settings that are mainly required to send emails:

  • SMTP Server/Host: It’s a server name. For example, smtp.gmail.com
  • SMTP Username: Your full email address. For example, yourname@gmail.com
  • SMTP Password: Your account password
  • SMTP port (TLS): 587
  • SMTP port (SSL): 465
  • SMTP TLS/SSL required: yes

Note: If you have your own email provider and you want to use that details then you can use that too.

Now we have all required details available, so we can go ahead and implement code to test mail using Gmail smtp.

HTML Markup Code To Send Mail – [.aspx]

Following is the complete HTML markup code for .aspx page shown as below:

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Send test mail using smtp settings in asp.net</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <table>
        <tr>
            <td>
                <h4>Send Email Using Gmail SMTP server settings in asp.net</h4>
            </td>
        </tr>
        <tr>
            <td>
                <asp:TextBox ID="txtToEmail" runat="server" Width="250" Height="28"
                    placeholder="To email: example@example.com"></asp:TextBox>
                <asp:RequiredFieldValidator ID="rfvToEmail" runat="server" ForeColor="Red"
                    ControlToValidate="txtToEmail" ErrorMessage="Required" Display="Dynamic">
                </asp:RequiredFieldValidator>
                <asp:RegularExpressionValidator ID="revToEmail" runat="server"
                    ControlToValidate="txtToEmail" ForeColor="Red" ErrorMessage="Invalid Email"
                    ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*">
                </asp:RegularExpressionValidator>
            </td>
        </tr>
        <tr>
            <td>&nbsp;&nbsp;</td>
        </tr>
        <tr>
            <td>
                <asp:TextBox ID="txtMessage" runat="server" placeholder="Your body message"
                    Width="250" Height="150" TextMode="MultiLine"></asp:TextBox>
                <asp:RequiredFieldValidator ID="rfvMessage" runat="server"
                    ControlToValidate="txtMessage" ForeColor="Red" ErrorMessage="Required">
                </asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td>&nbsp;&nbsp;</td>
        </tr>
        <tr>
            <td>
                <asp:Button ID="btnSend" runat="server" Text="Send Mail!" OnClick="btnSend_Click" />
            </td>
        </tr>
        <tr>
            <td>&nbsp;&nbsp;</td>
        </tr>
        <tr>
            <td>
                <asp:Label ID="lblMsg" runat="server"></asp:Label>
            </td>
        </tr>
    </table>
    </div>
    </form>
</body>
</html>

Following is the code that we need to use for sending emails, choose your language from below.

Send Email Using Gmail SMTP Settings Sample Code – [C#]

Add the following namespace that is required for sending emails:

using System.Net.Mail;

Now following is the code that we can use to send emails using MailMessage class:

protected void Page_Load(object sender, EventArgs e) {
}
protected void btnSend_Click(object sender, EventArgs e) {
    try {
        string Subject = "This is test mail using smtp settings",
        Body = txtMessage.Text.Trim(),
        ToEmail = txtToEmail.Text.Trim(); string SMTPUser = "yourname@gmail.com", SMTPPassword = "yourpassword";
        //Now instantiate a new instance of MailMessage
        MailMessage mail = new MailMessage();
        //set the sender address of the mail message
        mail.From = new MailAddress(SMTPUser, "AspnetO");
        //set the recepient addresses of the mail message
        mail.To.Add(ToEmail);
        //set the subject of the mail message
        mail.Subject = Subject;
        //set the body of the mail message
        mail.Body = Body;
        //leave as it is even if you are not sending HTML message
        mail.IsBodyHtml = true;
        //set the priority of the mail message to normal
        mail.Priority = MailPriority.Normal;
        //instantiate a new instance of SmtpClient
        SmtpClient smtp = new SmtpClient();
        //if you are using your smtp server, then change your host like "smtp.yourdomain.com"
        smtp.Host = "smtp.gmail.com";
        //chnage your port for your host
        smtp.Port = 25; //or you can also use port# 587
        //provide smtp credentials to authenticate to your account
        smtp.Credentials = new System.Net.NetworkCredential(SMTPUser, SMTPPassword);
        //if you are using secure authentication using SSL/TLS then "true" else "false"
        smtp.EnableSsl = true;
        smtp.Send(mail);
        lblMsg.Text = "Success: Mail sent successfully!";
        lblMsg.ForeColor = System.Drawing.Color.Green;
    } catch (SmtpException ex) {
        //catched smtp exception
        lblMsg.Text = "SMTP Exception: " + ex.Message.ToString();
        lblMsg.ForeColor = System.Drawing.Color.Red;
    } catch (Exception ex) {
        lblMsg.Text = "Error: " + ex.Message.ToString();
        lblMsg.ForeColor = System.Drawing.Color.Red;
    }
}

Send Email Using Gmail SMTP Settings Sample Code – [Vb.net]

Add the following namespace that is required for sending emails:

Imports System.Net.Mail

Now following is the code that we can use to send emails using MailMessage class:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
End Sub
Protected Sub btnSend_Click(ByVal sender As Object, ByVal e As EventArgs)
    Try
        Dim Subject As String = "This is test mail using smtp settings",
            Body As String = txtMessage.Text.Trim(), ToEmail As String = txtToEmail.Text.Trim()
        Dim SMTPUser As String = "yourname@gmail.com",
            SMTPPassword As String = "yourpassword"
        'Now instantiate a new instance of MailMessage'
        Dim mail As New MailMessage()
        'set the sender address of the mail message'
        mail.From = New MailAddress(SMTPUser, "AspnetO")
        'set the recepient addresses of the mail message'
        mail.To.Add(ToEmail)
        'set the subject of the mail message'
        mail.Subject = Subject
        'set the body of the mail message'
        mail.Body = Body
        'leave as it is even if you are not sending HTML message'
        mail.IsBodyHtml = True
        'set the priority of the mail message to normal'
        mail.Priority = MailPriority.Normal
        'instantiate a new instance of SmtpClient'
        Dim smtp As New SmtpClient()
        'if you are using your smtp server, then change your host like "smtp.yourdomain.com"'
        smtp.Host = "smtp.gmail.com"
        'chnage your port for your host'
        smtp.Port = 25 'or you can also use port# 587'
        'provide smtp credentials to authenticate to your account'
        smtp.Credentials = New System.Net.NetworkCredential(SMTPUser, SMTPPassword)
        'if you are using secure authentication using SSL/TLS then "true" else "false"'
        smtp.EnableSsl = True
        smtp.Send(mail)
        lblMsg.Text = "Success: Mail sent successfully!"
        lblMsg.ForeColor = System.Drawing.Color.Green
    Catch ex As SmtpException
        'catched smtp exception'
        lblMsg.Text = "SMTP Exception: " & ex.Message.ToString()
        lblMsg.ForeColor = System.Drawing.Color.Red
    Catch ex As Exception
        lblMsg.Text = "Error: " & ex.Message.ToString()
        lblMsg.ForeColor = System.Drawing.Color.Red
    End Try
End Sub

Conclusion

Done! You have learned about how to send email using Gmail in Asp.net Core. Now, you can implement it to your website and hope above article is useful. Please feel free to share this article if it is useful.

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