SMTP pick up directory for IIS website using web.config - will write all emails from application to file system in the folder specified instead of attempting to send.
<!--
After the </system.web> closing tag, insert the contents below between the <system.net> tags.
-->
</system.web>
<system.net>
<mailSettings xdt:Transform="Replace">
<smtp from="test@test.com.au" deliveryMethod="SpecifiedPickupDirectory">
<network host="localhost" />
<specifiedPickupDirectory pickupDirectoryLocation="d:\smtp\" />
</smtp>
</mailSettings>
</system.net>