Questions regarding POP3 vs. IMAP

Hello all,

I am writing a technical paper for one of my courses in college. As the title suggests, the paper is on the technical issues between POP3 and IMAP.

I have some experience working with IMAP, but nothing with POP3. I am doing research on both topics, but I thought it is nicer to hear from some people with experience with both protocols.

So far, I have a few questions, and they are as follows,

1) I heard that IMAP is supposed to be superior to POP3, but in what way?
2) I know IMAP sends the user name and password in clear text when TLS is not enabled, thus I am assuming POP3 does the same. Is this true?
3) During my research, I found that POP3 has a APOP command which uses MD5 with the system date and a “secret”. Is the APOP approach more secure compared to IMAP’s TLS?
4) Which protocol is faster (less stress on the server)?
5) Which protocol is more secure?
6) Which protocol is used more often by email servers?
7) I heard something about pop3 caching the user’s IP for up to 8 hours, is this true? If so, it is true across all implementations?

That’s all the questions I have for now.

Thanks

Ming

Comments inline...

It really is a matter of preference. I prefer IMAP because it supports folders and the like in a standard way. POP has some support for that but it isn't as well defined. Additionally, most POP3 servers do not let you store your email messages on the server. Therefore they get downloaded to the client (your PC for example). This makes it a real pain to have more than one machine from which you read email. With IMAP I have the exact same folder view and email messages on any IMAP client because all the data is really stored on the server.

Take a look at the RFC's for both IMAP and for POP. The standards both have clear text passwords available and they have encrypted options over SSL available.

TLS will be higher security.


I'd say that POP3 is. Because most files are stored on the client and not the server the server does not require some sort of backing store (usually a file system).


I'd say they are about the same.

I'd guess that POP3 is used by more because it is less stressful on the server. Additionally, POP3 has been around for a longer time and so it has some history behind it.

I have not heard of such a thing in any implementation. The RFC for POP3 does not mention anything of the sort.

Awesome stuff. Thank you very much for answering my questions. Now I have a more clear picture in my head about the direction of this paper, and I will go and read the RFCs and some technical papers on POP.

Hopefully I will be able to find some hard # about the pop and IMAP usage

Cheers

MIng