As admin, secretary, assistant, or Can-Do-Ologist, I've worked inside the very full inboxes of several very successful (and very swamped) folks in both the offline and online business worlds. A couple of times, people asked me for tips on getting responses from those very swamped folks. There's actually a lot of ground to cover on that topic, but here's the foundation: six tips for sending effective emails to busy people.
1. Introduce yourself–briefly.
This isn't the time to write those first eight chapters of your autobiography. There's no need to go overboard with your intro. On the flip side, though, give the recipient some context in which to place you. Did you meet at a conference? Are you a longtime reader of their blog? Just discovered their product thanks to a friend's referral? Say who you are and put a touch of context to it… and that's it.
2. Say what you want–briefly.
Don't make it hard for the reader to figure out how to respond to you. If you're asking for something, ask. If you want the reader to do something, say so. If you've got a question, ask it clearly and concisely. As with point #1, a bit of context can be helpful–but just a bit. Don't bury your request, question or need inside three paragraphs of marginally related facts or tangents.
3. Don't beg or threaten.
Begging should be reserved for desperation and sincere urgency, not as a way of distinguishing you from the crowd (which it will do, but probably not in the way you hope). And threats (“Do this or I'll write a blog post about how awful you are!” or “If you don't write me back, I'll have no choice but to unfollow you on Twitter and never be your friend again”), usually meant to be assertions of power, often come off as juvenile and desperate. Just don't.
4. Persistent and annoying are but a fine line apart. Don't cross it.
It's one thing to follow-up or ask again, but it's another to make showing up in your recipient's inbox one of your primary daily goals and habits. Once you slip over that line and get labeled as “annoying,” you keep that title. So the next time you show up in the recipient's inbox, even if it's weeks–or months–later, they think, “Oh great, it's that annoying guy.” That's not good. Unless the situation is urgent, it's probably better to err on the side of “less persistent,” to avoid falling into the hard-to-shake category of annoying.
5. Give the recipient adequate time to respond.
By “adequate” I mean plenty of time, not “until you get antsy.” Very few emails are actually emergencies, so don't treat all your communications as though they require immediate attention. Wait at least a full day before following up, but preferably even longer (several days to a week) unless you've got a specific reason–other than impatience–to follow up sooner.
6. Give the recipient the benefit of the doubt.
Even if he takes longer to respond than you'd prefer, your recipient is probably not ignoring you, or trying to swindle you, or being a terrible person, or recklessly disregarding your needs. Even though we all use email, how we use it varies widely–we don't all use it the same or give it the same priority or check and respond to it on the same time schedule. How we interpret the lack of a response within a certain timeframe almost certainly tells us a great deal more about how we value and use email than it does about how the recipient views or values us and our communication.