1. Exchange Protocols Overview
Andrew Davidoff
Senior Software Engineer
Microsoft Corporation

2. Agenda
Brief introduction to Exchange Server Open Specifications An overview of the protocol architecture for Exchange Important protocol families that are used to communicate with Exchange Server

3. Introduction to Open Specifications
Normative language
Designed to document bits over the wire
No APIs – only Protocols
Normative and informative content
Follows RFC 2119
MUST, SHOULD, MAY are used to document version-specific behavior
Strict document structure
Windows/Exchange or product API knowledge not required…
Microsoft Products are not mentioned in normative content, only in endnotes
We are striving to make our Open Specifications complete, accurate and implementable

4. Exchange Protocols

5. Overview Document [MS-OXPROTO]
Defines Exchange protocol families
Informative and Scenario-Based
How multiple protocols work together in typical scenarios
How to complete the same task using different protocol families
Walkthroughs and examples
Send via RPC/ROPs, EWS, or Exchange ActiveSync
Resolve a recipient from an Address Book
Synchronize items
Provision mobile client using Exchange ActiveSync
Many other scenarios

6. Protocol families Remote Operations (a.k.a. RPC)
Exchange Web Services (EWS)
Exchange ActiveSync (EAS)
Other groups of protocols
Autodiscover
Name Service Provider Interface (NSPI)
Content Conversion
Standards Support

7. Client communication with Exchange
Exchange Server
Smartphone/Tablet
EAS
Storage
EWS
Mailbox store
Outlook for MAC
Public store
RPC/ROPs
OAB
Non-Exchange SMTP
NSPI
Outlook for Windows Desktop
Auto-Discover
Exchange SMTP
POP/IMAP
SMTP
POP/IMAP Client

8. Exchange RPC/ROPs protocols
Implemented in some form from “Day 1” (such as Exchange 4.0), extended and re-architected several times Low-level access to Exchange Storage Workhorse for Outlook communication with Exchange Used by MAPI Transport layer: ROPs (Remote Operations) within an RPC binary blob Optimized to minimize traffic on the wire; very complex parsing RPC can use HTTP(S) or TCP connections (HTTP(S) only in Exchange 2013) New [MS-OXCMAPIHTTP] as alternative to use ROPs over HTTP; no RPCs

9. Exchange RPC/ROPs: Transport
Header
Binary Blob
(EcDoRpcExt2)
RopSize
ROP1
ROP2 …
HSOT Table
RopID
ROP Data
RopID
ROP Data
Note: No ROP Data size or end marker.
Every ROP Data in the blob must be parsed.
Every RopID has different ROP Data structure.
Number of documented RopIDs: 130

10. RPC/ROPS protocols - continued
RPC/ROPs protocols define both Exchange (server) and Outlook (client) behaviors Client is handling most of low-level processing and logic behind complex items – messages, folders, calendar items, contacts, tasks, etc. Naming: [MS-OXO*] and [MS-OXC*] (few exceptions) 40+ Protocols, ~3000 pages

11. Exchange Web Services (EWS)
Alternative to RPC protocols
Higher level of abstraction compared with RPC protocols
In Exchange RPC world, it is the responsibility of the client to implement tasks, contacts, calendars, etc. EWS (and EAS) implement them on server side in a way that is interoperable with Outlook.
First implemented in Exchange Server 2007
Outlook uses subset of EWS protocols
Unified Messaging, MailTips, Availability, OOF, Office Apps, Room List, Archive, Mailbox Policies, Calendar Sharing, Site Mailboxes, etc.
New Exchange features tend to be implemented in EWS

12. Exchange Web Services (EWS) - continued
Lync/Skype and SharePoint use several EWS protocols to communicate with Exchange Server Outlook for Mac is built on EWS Mac OSX Snow Leopard has EWS support via Apple’s Mail application Exchange LOB applications should use EWS Transport: Naming: [MS-OXW*] 43 Protocols, ~2000 pages
SOAP
HTTP/HTTPS

13. Exchange ActiveSync (EAS)
High level of abstraction, similar to EWS in complexity, limited set of objects and features Designed to be used by smartphones and handhelds Industry standard, several non-Exchange Server implementations Wide range of clients – Windows 8, iOS, Android, … even Outlook to Hotmail Transport: Naming: [MS-AS*] 15 Protocols, ~900 pages
WBXML
HTTP/HTTPS

14. Other Exchange protocols
NSPI (Address Book) Directory/Profile Services (Autodiscover) Content Conversion, how Internet (RFC-based) content gets converted to Exchange objects and back Standards-based protocols – Extensions and Compliance [MS-OXPROTO] is a good reference Exchange WebDAV protocols – deprecated

15. Exchange test tools update
New parsers for Message Analyzer Protocol families: EAS, EWS, RPC, and MAPIHTTP Retirement of Exchange RPC Extractor (RPX) New test suites for EAS, EWS, RPC, and MAPIHTTP

16. Summary
Many options are available when developing with Exchange protocols; choose the protocol family carefully. There are a lot of resources to assist with your development (most are free) that you can take advantage of. Many interoperability tools (test suites, parsers, etc.) are already available.

17. Exchange protocols resources
All Exchange protocol documents
Microsoft Message Analyzer
Protocol Test Suites
Help with Open Specifications:
Office Interoperability blog:

18. Mail, Calendar, and Contacts REST APIs
Andrew Davidoff
Senior Software Engineer
Microsoft Corporation

19. Why use REST APIs? Hundreds of millions of Users
Office 365, Outlook.com; hybrid and on-premises on the roadmap
Powerful, easy, and intuitive way to access and manipulate Office 365 data
Granular, tightly scoped permissions to access user data
Based on open standards – OAuth 2.0, JSON, ODATA v4.0
Web-friendly APIs to enable web and mobile applications developers

20. What do the REST APIs in Office 365 offer?
Active Directory
Exchange & Outlook.com
SharePoint
Sites
OneDrive
Mail
Users
OneDrive for Business
Calendar
Client API
Contacts
Groups
Sites, Lists and Libs
Search
O365 Groups
Workflow …

21. Common Consent Framework
Single Authentication flow for O365
Azure AD Graph, Exchange, SharePoint
Device apps and web apps
Admin and end-user consent
Secure protocol
OAuth 2.0 authorization
No capturing of user credentials
Fine-grained access scopes
Supports multi-factor authentication (MFA) and federated user sign-in
Long-term access through refresh tokens

22. Discovering endpoints and APIs
Office 365 discovery services
Rich service metadata
Lists all entities, collections, actions, complex types, enumerations and their properties
For example:

23. Rich tooling .NET SDK to build many types of apps using Visual Studio
.NET Windows Store Apps
Windows Forms Applications
WPF Applications
ASP.NET MVC Web Applications
ASP.NET Web Forms Applications
Xamarin Android and iOS Applications
Multi-device Hybrid Apps (Cordova)
Android and iOS SDKs

24. You’ve got mail! Permissions Entities, Collections, Actions Samples
Read, Read+Write, Send
Entities, Collections, Actions
Samples
Entity
Collection
Actions
Folder
Folders
CRUD, Copy, Move
Message
Messages
CRUD, Copy, Move, Reply, ReplyAll, Forward, Send, CreateReply, CreateReplyAll, CreateForward 
Attachment
Attachments
CRUD
Entity
Collection
Intuitive Send API

25. No client-side recurrence expansion required
Calendar – 4?
Permissions
Read, Read+Write
Entities, Collections, Actions
Samples
& endDateTime=
Entity
Collection
Actions
CalendarGroup
CalendarGroups
CRUD 
Calendar
Calendars
Event
Events
CRUD, Accept, Decline, TentativelyAccept
CalendarView
N/A
Read
Attachment
Attachments
CRUD
No client-side recurrence expansion required
Entity
Collection

26. Contacts – Your number again?
Permissions
Read, Read+Write
Entities, Collections, Actions
Samples
Use Azure Active Directory API to find users in an O365 organization (tenant)
Entity
Collection
Actions
ContactFolder
ContactFolders
CRUD
Contact
Contacts

27. Demo
Sample REST API Requests

28. Rich query syntax using OData
Scenario
URL
Get 5 messages from Inbox
Get the next 10 messages
Get top 10 messages sorted by DateTimeReceived
Get selective properties on messages
Get events starting after a particular DateTime
ge T20:00:00Z
Get calendar view for a week with selected properties, latest events first
Get # of messages with attachment(s)
eq true
Get count and selected props on messages with attachment(s)
Get contact with a given name
eq 'John'

29. Roadmap
Enable end-to-end scenarios – with focus on web and mobile applications
Notifications
Custom/Extended properties
Sync
Free/Busy
Mail tips, OOF settings
Delegate scenarios
On-premises Exchange Server 2016 support for REST APIs is coming
Support for Exchange Server 2013 is on the roadmap as well
Outlook.com accounts can be accessed by REST APIs
Different endpoint, same principles
New Unified (Graph) APIs coming very soon
The same REST APIs to access Exchange, SharePoint, Active Directory, and One Drive for Business data
Perfect for complex workflow-based solutions

30. Code samples on GitHub Plenty of sample code on GitHub
MailSim tool now supports REST APIs
Two implementations: using SDK or direct HTTPS
Includes code that does Authentication (OAuth2) in both implementations
More Open Source Applications are in the works

31. http://dev.office.com REST API Resources Sign up Explore Training
Explore
Training
API endpoints for China

32. Questions?