Users are rational
Here is something important to remember about your users:
Users are rational.
Users aren't crazy, and they don't do things just to irritate you; what they do and what they report about problems is not crazy from their perspective, however odd it looks from yours. If users report 'I cannot log into the intranet' when they cannot log in to the IMAP server, it is not because they are stupid, it is because 'the intranet' is how they think about your system.
(The answer to 'how can they be so ignorant?' is that they don't care to learn the details, any more than most people care to learn the details about how their phone service, their plumbing, or their car work. Everyone has massive areas of ignorance in their life; it's how we deal with a very complicated world.)
I think that it is especially easy for system administrators to fall into this mindset, because we see our systems so clearly that we can easily miss how other people don't and how complicated things are from an outside perspective and so on. (Plus, there is a cultural tradition of sysadmins thinking of their users as stupid, however ill advised this is, with all sorts of supporting cultural institutions and mythology.)
One of the corollaries of this is that how users refer to things gives you valuable clues about their mental model of your systems. This is not just useful for understanding problem reports and requests; it's very important for building systems that behave predictably and do what the users want, and making sure that the users have an accurate mental model of what is going on is vital in avoiding terrible mistakes.
(This is closely related to how users are almost always right.)