How Letsencrypt work for windows IIS?


Thanks @schoen for your answer. I’ll investigate that option, but I think I’m out of luck.


Hello all,

Thanks @LoneCoder for the fine tool that worked almost seemlessly, it did raise an exception while trying to delete the folder structure saying directory not empty both first testing and then when for real. Thanks also to @NetoMeter for the nice tutorial. Although all went fine, by checking the certificate it says that it is expired or not yet valid. Did i miss something?

Thank you for your help in advance.



No, you didn’t.

If you see this warning in EMC, this means the Exchange server is not able to connect to the Internet and validate the certificate. That’s not something specific to the LE certificates but applicable to any certificate you install on the Exchange server - the server tries to connect and verify the certificate is valid (and not revoked for example).

Check whether the Exchange server has access to the Internet on port 80 and 443 (I don’t remember whether the check was performed over https)


Hi Schoen,

The Letsencrypt Win Simple client supports only the HTTP-01 challenge.