Clarifying terminology: MAPI vs RPC/HTTPS vs Outlook Anywhere

exchange exchange-2010 exchange-2003 outlook-anywhere

7,711

outlook anywhere is RPC over HTTP - it's just a name change. Outlook anywhere's auto configuration is an outlook 2010 ability. Older clients can still use outlook anywhere but must be manually configured. An additional feature (under the outlook anywhere umbrella) is client redirection, which you would set up if you wanted to use SSL or a specific CAS server for a client or group of clients that were not domain joined.

7,711

Author by

Juanjo Daza

Updated on September 18, 2022

Comments

Juanjo Daza over 1 year
Will someone correct or verify my understanding of the following terms:

MAPI (sometimes referred to as TCP)
1. The on-the-wire RPC protocol format that Outlook uses with Exchange server. The client connects to server ports 135 and 139 (among others) to facilitate communication.
2. It is a C++ API. The resulting API call sends out a network packet based on the MAPI profile configuration (HTTPS or RPC based)
Image of a TCP/MAPI client connection:

RPC over HTTPS (sometimes referred to RPC/HTTPS, RoH, or HTTPS)
- First introduced with Outlook 2003 and Exchange 2003, RPC/HTTPS tunnels MAPI-based RPC traffic into the HTTP protocol where a CAS server or Front End server proxies the connection to the back end server.
Outlook Anywhere
- This is the same thing as RPC/HTTPS, with the added logic of using Autodiscover to locate and configure a MAPI-based mail profile. The resulting configuration may use RPC or HTTPs on-the-wire.
Image of a RPC/HTTPS, OutlookAnywhere, or HTTPS client connection
- MichelZ almost 12 years
  
  Seems to be OK for me. MAPI is not only Outlook, but a general "Messaging API", not only used by Outlook
- Juanjo Daza almost 12 years
  
  @MichelZ - I realized that after I posted... refresh and let me know if I made the change you want me to make.
- MichelZ almost 12 years
  
  Seems to be OK now, yap
- Massimo almost 12 years
  
  The base port for RPC is 135, not 139.
- Juanjo Daza almost 12 years
  
  @Massimo I wrote 139 twice... was thinking 135. Thanks.
Massimo almost 12 years

Autodiscover was introduced in Outlook 2007/Exchange 2007.
raja almost 12 years

autodiscover perhaps, but I don't think it had autoconfig (I think you had to use RPC over HTTP without site configs)- I certainly could be wrong