Is it possible calling a Webservice using NTLM authentication from apex?
It is a Microsoft Navision Webservice, I tried to do it in Java following this guide and it works.
Answer
I was working on a project that required SalesForce to call a service that used NTLM authentication. I ended up writing a client implementation of NTLM in apex that you can re-use. I’ve hosted it on github here:
https://github.com/natewallace/ApexNTLM
Upload all of the classes into your org and then use the HttpClient class to send messages to your NTLM secured service.
Attribution
Source : Link , Question Author : Giovanni Oregioni , Answer Author : Nate Wallace