SMTP Impostor (formally SMTP Server for Developers)

Project Description
SMTP Server Emulation

Version 2.0 now available as a clickonce install and a standalone (see downloads)

Here's the write up
http://antix.co.uk/projects/smtpimpostor

Here's the download (click once)
http://antix.co.uk/projects/smtpimpostor/2/Setup.exe

Here's the write up
http://antix.co.uk/projects/smtpserverfordevelopers

Here's the Click Once auto updating setup
http://antix.co.uk/projects/SMTPServerForDevelopers/Setup.exe

There is a standalone setup also available in the downloads tab too