Please change the code and check...
MailAddress mailFrom = new MailAddress(GetAppSettingValue(Constants.K_APP_KEY_MAIL_FROM));
MailAddress mailTo = new MailAddress(mailToAdd);
using (MailMessage message = new MailMessage(mailFrom, mailTo))
{
message.Priority = MailPriority.Normal;
message.Subject = "mailSubj";
message.Body = "mailBody";
if (!additionalToAdd.IsNull())
{
message.To.Add(new MailAddress(additionalToAdd));
}
SmtpClient client = new SmtpClient();
client.Send(message);
}
In web config add the following
<system.net>
<mailsettings>
<network enablessl="true" host="smtp.gmail.com" port="587" username="test@abc.com" password="password" />
<smtp from="password" deliverymethod="SpecifiedPickupDirectory">
<specifiedpickupdirectory pickupdirectorylocation="D:\00TestEmails\" />
</smtp>
</mailsettings>
</system.net>
Use any of the above line either network or smtp.
The first one is used to send mail..while the 2nd is used to stored the mail in the specified directory place.
Hope it will help you.