Performance: IMAP vs POP vs WebDAV (Exhange)

Question

I use VS 2008, .net 3.5, C# and Exchange 2003 server.

I want to access inbox in Exchange and read messages and perhaps attachaments.

I'm desperately looking for some statistics (high performance) about usage of POP versus IMAP versus WebDAV Exchange-MAPI, especially in professional context.

WebDAV has more performance than Imap and POP3 ?

Answer 1

POP, IMAP and WebDAV are protocols.

How do you measure protocol performance and more importantly compare them?

It is not easy as they function a bit differently. POP provides for offline access while with IMAP you predominantly operate online. Depending on the context, offline operations can have it's advantages but if you are operating out of multiple clients, it can become a pain.

IMAP on other hand does a lot of online performance optimizations. The key idea is to defer transferring of information till it is clear that it is required or is what the client has requested.

These include

1. The ability to fetch the structure of a message without downloading it,
2. To selectively fetch individual message parts.
3. The ability to use the server for searching in order to minimize data transfer between client and server.

Some of these advantages hold well for webdav based access to since query etc can defer the execution of query to server and return the filtered data.

How ever, in another context(Not yours), if the data is available offline already then all processing avoid network access and will result on increased performance due to offline capabilities.

So what you are looking for, is performance of particular implementation of these protocols.

The conditions can be varying but you should be able to test out the basic operations that you are looking for. For example how does the server performance vary with increased data etc.

1. For fetching data from inbox and attachments, it should be easy to test out the server with varying data sizes.