This question came to me after reading this question and its comments.
EDIT: The question is now posted.
In my opinion, setting emacs up to read and/or write mail is hard. And given how many packages exist to achieve this, it shouldn't be that hard. I have stopped counting how many people (including myself, mental voice version) told me "Mail with emacs? Oh, yes, I tried this and that, and this happened, then I gave up". I know many emacs fanatics, only one of them reads his mail with emacs. He writes them with something else.
Yet it is also something that a lot of people want to do at some point.
There is an overview on mail packages on the emacs wiki: http://www.emacswiki.org/emacs/CategoryMail This surely is a very nice and encouraging entry point for beginners ("sarcasm")!
In my opinion, the emacs.sx website is one of the best place that the internet can offer to have a list of mail solution for emacs which would be:
- nicely formatted (no need to dive through three layers of pages to read the essentials about a package)
- nicely sorted (votes should give an overview of popularity, and implicitely usability, of a package)
- curated (obsolete packages would be marked as such, etc)
This list would contain a very basic community-wiki question (as broad as possible, to be available as a duplicate candidate for as many questions as possible on that topic), and then one answer per package or solution.
As an example of how this can work without being a mess, you can see this list of latex IDEs, and the associated meta question which became necessary at some point. I don't think we'd need to go as far as tex.sx for that (no need to have nominated curators, for example), but should this list appear, it would be a good idea to agree beforehand on a template for answers, for example.
This template could include information such as external dependencies, supported protocols, authentication protocol, password storage method, support for offline work...
One last point: as I understand it, a lot of the difficulties come from the email protocols rather than emacs, and users underestimating the number of tools required to recieve or send a mail. Maybe an extra accepted answer (to be above the list) could be used to sum this up, and explain exactly where does emacs come into play. On the other hand, I believe that this explanation could be rather off-topic on this site, so it could probably be replaced by a link to another sx site about the question.