How does linkedin import contacts from outlook?

Linkedin has a feature that allows users to enter their outlook credentials and imports their outlook contacts.

I am trying to emulate this functionality, in a php application.

So far, the only way I have discovered on how this might be done is through Exchange web Services. https://emailhost/EWS/Services.wsdl I am using the php-ews library to try and connect to ews.

I was hoping for some sort of information on a defacto way to retrieve contacts given a users credentials, but have been unable to find much information on this at all.

Are there any other ways that this could be accomplished other than EWS? Does anyone know how linkedin is doing this?

Answer

Given that this feature works for a random end user, I don’t think LinkedIn connects to Exchange (through EWS or any other API), but to the Outlook instance on the users’ machine.

Accessing Outlook objects on a local machine can be done in any programming language through old-fashioned OLE automation. This will also let LinkedIn retrieve contacts for accounts connected to other servers, like e.g. Lotus Notes. (Although I cannot confirm that LI actually does that).