Classic ASP/General - DKIM / DomainKey on IIS SMTP using VBScript/ASP

Hi friends,

Greeting for the day!

I am sure many of us must have encountered that the mails sent from our application doesnt land up in Yahoo or Hotmail or many other email providers. Unfortunately many times not even in the Spam Folder.

After going through various sites I found that Yahoo Mail is somehow making its DKIM/DomainKeys a very important tool to counter spam. And this is why many of the email providers have implemented and support the same including Gmail and many others. Even when I see mails from Facebook it is even signed with DKIM.

There is not much documentation on implementing the same for IIS Smtp to support DKIM except one software which comes at a good price of $279. Which I feel is too high for many site owners.

I am sure we can make it work for free and the process is:

a) IIS SMTP has a feature Event sink which also supports scripting support and we can process all the emails that comes in.

b) We would require a script that will need to read the mail and create the DKIM signature based on RFC 2781 on it and update the same. It requires RSA SHA1 hash.

c) Publish the Public key on the DNS.

I am willing to work on the same and would appreciate if someone would like to give their suggestions if they have already worked on it.

Cheers,
Vijay