Hello,
I am currently writing a client to access a Microsoft Exchange server and read contacts, appointments etc. from it.
Through days of searching I\'ve be
Your first check should not use any complex scripting. Instead try opening the WDSL from a simple browser window on the Debian machine like so: https://your.exchange-server.com/EWS/Services.wsdl
If that does not work there are probably access restrictions in place that depend on the client IP or client network (e.g. your development machine being in a trusted network, your Debian not). The fact that you get a 401 ("Unauthorized" - request requires user authentication) suggests that there is no problem with contacting the server but with authentication.
Another check I suggest is that you have a look into your phpinfo() to make sure your PHP installation on Debian is capable of handling HTTP*S* requests. Make sure, OpenSSL is installed!