http://www.dotnetcurry.com/ShowArticle.aspx?ID=65

HTH,

Suprotim Agarwal

code to Send Mail:

C#

using System.Net;
using System.Net.Mail;
-----------------------

        public static bool SendMail(string strFrom, string strTo, string strSubject, string strMsg)
        {            
            try
            {                
                // Create the mail message
                MailMessage objMailMsg = new MailMessage(strFrom, strTo);
                
                objMailMsg.BodyEncoding = Encoding.UTF8;
                objMailMsg.Subject = strSubject;
                objMailMsg.Body = strMsg;
                objMailMsg.Priority = MailPriority.High;
                objMailMsg.IsBodyHtml = true;

                //prepare to send mail via SMTP transport
                SmtpClient objSMTPClient = new SmtpClient();
                objSMTPClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis;
                objSMTPClient.Send(objMailMsg);
                return true;                
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }     

  
VB:

Public Shared Function SendMail(ByVal strFrom As String, ByVal strTo As String, ByVal strSubject As String, ByVal strMsg As String) As Boolean
			Try
				' Create the mail message
				Dim objMailMsg As MailMessage = New MailMessage(strFrom, strTo)

				objMailMsg.BodyEncoding = Encoding.UTF8
				objMailMsg.Subject = strSubject
				objMailMsg.Body = strMsg
				objMailMsg.Priority = MailPriority.High
				objMailMsg.IsBodyHtml = True

				'prepare to send mail via SMTP transport
				Dim objSMTPClient As SmtpClient = New SmtpClient()
				objSMTPClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis
				objSMTPClient.Send(objMailMsg)
				Return True
			Catch ex As Exception
				Throw ex
			End Try
End Function
 

Code to send mail with attechment.,

        public static bool SendMail(string strFrom, string strTo, string strSubject, string strMsg)
        {            
            try
            {                
                // Create the mail message
                MailMessage objMailMsg = new MailMessage(strFrom, strTo);
                
                objMailMsg.BodyEncoding = Encoding.UTF8;
                objMailMsg.Subject = strSubject;
                objMailMsg.Body = strMsg;
                Attachment at = new Attachment(Server.MapPath("~/Uploaded/txt.doc"));
                objMailMsg.Attachments.Add(at);
                objMailMsg.Priority = MailPriority.High;
                objMailMsg.IsBodyHtml = true;

                //prepare to send mail via SMTP transport
                SmtpClient objSMTPClient = new SmtpClient();
                objSMTPClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis;
                objSMTPClient.Send(objMailMsg);
                return true;                
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }        

 hope it helps./.

is there maximum size of attachment

Here is how I use to send e-mail from the web feedback form (the code is  VB), and I am using server credentials:

Imports System.Net.Mail

Partial Class ContactsEnglish
    Inherits System.Web.UI.Page

    Protected Sub send_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles send.Click
        If Page.IsValid() Then
            Dim mySmtpClient As New SmtpClient
            Dim myMail As New MailMessage
            Dim myFrom As New MailAddress(email.Text)
            Dim myTo As New MailAddress("recipients_email@server.com")
            myMail.BodyEncoding = System.Text.Encoding.UTF8
            myMail.To.Add(myTo)
            myMail.From = myFrom
            myMail.Subject = "Mail's subject goes here"
            myMail.Body = vbCrLf & "Country: " & country.Text & vbCrLf & vbCrLf & "Name: " & name.Text & vbCrLf & vbCrLf & "Phone number: " & phone.Text & vbCrLf & vbCrLf & "E-mail: " & email.Text & vbCrLf & vbCrLf & "Inquiry: " & inquiry.Text
            mySmtpClient.Host = "www.YourMailServer.com"
            mySmtpClient.Credentials = New System.Net.NetworkCredential("YourMail@server.com", "YourMailPassword", "www.YourMailServer.com")
            Try
                mySmtpClient.Send(myMail)
                lbl.Text = "Your message has been sent. Thank you !"
            Catch ex As Exception
                lbl.Text = "Sending failed !"
            End Try
        End If
    End Sub
End Class

P.S.

This mail will  be sent in text format. The asp's controls that I am using  are 5 text boxes, button send and validation controls for the requred field.

Hope it helps

Regards

Heres another one - In ASP.NET 2.0 using VB also attaching a file like shown above

    Public Shared Function SendMail(ByVal strFrom As String, ByVal strTo As String, ByVal strSubject As String, ByVal strMessage As String) As Boolean
        Try
        Dim MySmtpClient As New System.Net.Mail.SmtpClient("Your SMTP Server")
        MySmtpClient.Credentials = New System.Net.NetworkCredential("Your-username", "Your-password")
        Dim msg As New System.Net.Mail.MailMessage(strFrom, strTo, strSubject, strMessage)
        msg.BodyEncoding = Encoding.UTF8
        msg.IsBodyHtml = True
        msg.Priority = Net.Mail.MailPriority.High

        'Add an Attachment
        Dim at As New System.Net.Mail.Attachment(Current.Server.MapPath("~/Uploaded/txt.doc"))
        msg.Attachments.Add(at)

        MySmtpClient.Send(msg)
        Return True

        Catch ex As Exception
            Throw ex
        End Try
    End Function

Please check on the link below

http://www.worldofasp.net/aspnet/Tutorials/Email_ASP.NET2/Sending_Email_in_ASP.NET_2.0_83.aspx