Hello MauryaIsha,

Last year I made something similar in one of my projects, so maybe you could use this approach below:

        public static bool SendMail(string MailAddressTo, string MailMessage, string AttachedFileName)
        {
            Attachment AttFile = null;
            string OriginalMailAddressTo = MailAddressTo;
            try
            {
                SmtpClient smtpClient = new SmtpClient();
                MailMessage message = new MailMessage();
                smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
                smtpClient.Host = Properties.Settings.Default.MailServer;
                smtpClient.UseDefaultCredentials = Properties.Settings.Default.MailCredentials;
                if (!Properties.Settings.Default.MailCredentials) smtpClient.Credentials = new NetworkCredential(Properties.Settings.Default.MailUsername, Properties.Settings.Default.MailPassword);
 
                MailAddress MailAddressFrom = new MailAddress(Properties.Settings.Default.MailAddress);
                message.From = MailAddressFrom;
 
                // Цикъл по адресите до които ще се изпраща e-mail ако са повече от един разделени с ";"
                while (MailAddressTo.Length > 0)
                {
                    int charIndex = MailAddressTo.IndexOf(';');
                    if (charIndex == -1)
                    {
                        try
                        {
                            message.To.Add(MailAddressTo);
                            break;
                        }
                        catch (Exception ex)
                        {
                            EventLog.WriteEntry(ImsDataExchangeService.sSource, "Incorrect e-mail address <" + MailAddressTo + "> " + ex.ToString(), EventLogEntryType.Warning);
                        }
                    }
                    else
                    {
                        string currentAddress = MailAddressTo.Substring(0, MailAddressTo.IndexOf(';'));
                        try
                        {
                            message.To.Add(currentAddress);
                        }
                        catch (Exception ex)
                        {
                            EventLog.WriteEntry(ImsDataExchangeService.sSource, "Incorrect e-mail address <" + currentAddress + "> " + ex.ToString(), EventLogEntryType.Warning);
                        }
                        MailAddressTo = MailAddressTo.Remove(0, charIndex + 1);
                    }
 
                }
                message.Subject = Properties.Settings.Default.MailSubject;
                message.IsBodyHtml = false;
                message.Body = MailMessage;
 
                if (AttachedFileName != null)
                {
                    AttFile = new Attachment(AttachedFileName);
                    message.Attachments.Add(AttFile);
                }
                smtpClient.Send(message);
                if (AttachedFileName != null) AttFile.Dispose();
                return true;
            }
            catch (Exception ex)
            {
                EventLog.WriteEntry(ImsDataExchangeService.sSource, "GENERAL ERROR: It is not possible to send the message to " + OriginalMailAddressTo + ". " + ex.ToString(), EventLogEntryType.Warning);
                return false;
            }
        }

When you press your Button you should call this method. Please provide information about recipient, message and file that will be attached to this e-mail. The attachment (whole e-mail) will be visible in Sent Items folder of your account.

Please let me know if you have any questions