Support Exchange Server - EWS Managed API 2.0

[nickgrealy]

Corporate mail servers are moving to cloud based exchange office 365 and many will no longer support/allow IMAP connectivity (** needs citation).

Provide an option to connect via "EWS Managed API 2.0" to facilitate future MS Exchange integration.

Operating system: N/A
Jenkins Version: N/A
Plugin Version: N/A
Mail Server: MS Exchange Server 2010 / Office365

[nickgrealy]

I don't currently have bandwidth to implement this - I'd be grateful if anyone want's to step in and offer a PR.

[nickgrealy]

Additional resources: (thanks Robert D. McDonnell!)

https://msdn.microsoft.com/en-us/library/office/dd633709(v=exchg.80).aspx

With a quick search I found two libs :

https://github.com/OfficeDev/ews-java-api
https://github.com/ecederstrand/exchangelib