Asking people how they work in real life is not usually that productive. People often don't really know how they work -- they just work -- and will tell you what they think that they do rather than what they really do.
If you have identified a target market (and if you haven't, then that's what you should do first), then the best thing to do is find a way to watch your target market work in their native environment. This is ideal, but can be hard to swing.
For instance, if your target is narrow enough, you could land a short-term contract gig with a company that fits it, then you'll learn first-hand how things really work and what the pain points are. A bonus to doing that is that it adheres to another principle I believe in -- to the greatest degree possible, each of your activities should generate income in at least two different ways. In this case, you'd get a paycheck as well as free market research.
There are other methods, too. For instance, take members of your target market out to lunch and talk shop. Don't try to sell them on anything at all -- in fact, don't talk about your product. Instead, get them talking about their daily work routine. They may not open up at first, but they'll probably start telling you valuable things on the second or third lunch, or after a cocktail.
That asymmetry -- valuing your own time more than clients -- is intuited by most people. You're sending emails and expecting people to go out of their way at your request. It's convenient for you and inconvenient for them. It doesn't express an appreciation for their business at both levels. Their business with you and their business as a set of operations with a set of problems.
I'm not suggesting visiting every user all over the world. I am suggesting that a good way to understand what your users are doing is to see what they are doing. Visiting makes it easy for your users to show (not tell) you what they are doing.
I definitely understand the idea of knowing how my clients work and operate in real life, so I keep asking them via email. Unfortunately, every time, they are all quite reticent to share more about their business.
I might be asking wrong...