Send Bulk (Mass) Email with multiple attachments using GridView in ASP.Net

Hi smile,

Refer below code.

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:CheckBox ID="chkSelect" runat="server" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="30" />
        <asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="150" />
        <asp:TemplateField HeaderText="Email">
            <ItemTemplate>
                <asp:HyperLink ID="lnkEmail" runat="server" Text='<%# Eval("Email") %>' NavigateUrl='<%# Eval("Email", "mailto:{0}") %>' />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

<table border="0">
    <tr>
        <td>File Attachments:</td>
        <td>
            <asp:FileUpload ID="fuAttachment" runat="server" AllowMultiple="true" /></td>
    </tr>
    <tr>
        <td></td>
        <td>
            <asp:Button Text="Send Bulk Email" runat="server" OnClick="SendBulkEmail" /></td>
    </tr>
</table>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                    new DataColumn("Name", typeof(string)),
                    new DataColumn("Email",typeof(string)) });
        dt.Rows.Add(1, "John Hammond", "john.hammond@test.com");
        dt.Rows.Add(2, "Mudassar Khan", "mudassar.khan@test.com");
        dt.Rows.Add(3, "Suzanne Mathews", "suzzane.mathews@test.com");
        dt.Rows.Add(4, "Robert Schidner", "robert.schidner@test.com");
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}

protected void SendBulkEmail(object sender, EventArgs e)
{
    //Create a temporary DataTable
    DataTable dtCustomers = new DataTable();
    dtCustomers.Columns.AddRange(new DataColumn[2] { new DataColumn("Name", typeof(string)),
                    new DataColumn("Email",typeof(string)) });

    //Copy the Checked Rows to DataTable
    foreach (GridViewRow row in GridView1.Rows)
    {
        if ((row.FindControl("chkSelect") as CheckBox).Checked)
        {
            dtCustomers.Rows.Add(row.Cells[2].Text, (row.FindControl("lnkEmail") as HyperLink).Text);
        }
    }

    string subject = "Welcome Email";
    string body = "Hello {0},<br /><br />Welcome to ASPSnippets<br /><br />Thanks.";

    List<Attachment> attachments = new List<Attachment>();
    foreach (HttpPostedFile file in fuAttachment.PostedFiles)
    {
        string fileName = Path.GetFileName(file.FileName);
        file.SaveAs(Server.MapPath("~/Uploads/") + fileName);
        attachments.Add(new Attachment(file.InputStream, fileName));
    }

    //Using Parallel Multi-Threading send multiple bulk email.
    Parallel.ForEach(dtCustomers.AsEnumerable(), row =>
    {
        SendEmail(row["Email"].ToString(), subject, string.Format(body, row["Name"]), attachments);
    });
}

private bool SendEmail(string recipient, string subject, string body, List<Attachment> attachments)
{
    MailMessage mm = new MailMessage("sender@gmail.com", recipient);
    mm.Subject = subject;
    mm.Body = body;
    mm.IsBodyHtml = true;
    if (attachments.Count > 0)
    {
        foreach (Attachment attachment in attachments)
        {
            mm.Attachments.Add(attachment);
        }
    }
    SmtpClient smtp = new SmtpClient();
    smtp.Host = "smtp.gmail.com";
    smtp.EnableSsl = true;
    NetworkCredential NetworkCred = new NetworkCredential();
    NetworkCred.UserName = "sender@gmail.com";
    NetworkCred.Password = "<password>";
    smtp.UseDefaultCredentials = true;
    smtp.Credentials = NetworkCred;
    smtp.Port = 587;
    smtp.Send(mm);

    return true;
}

Refer given article too.

Send email with multiple attachments using Multiple FileUpload control in ASP.Net 4.5