Let’s face it — none of us like to be ignored. But sending an e-mail to a colleague that commits even ONE of these four cardinal sins can mean the difference between a speedy reply … and that big e-mail receptacle bin in the sky. :-/
Here are four common reasons why YOUR mail could be going “the way of the spam”, and how to reverse them to get your messages answered — and answered *fast*:

1. “Can you hear me now? Durn! Can you hear me now? Frick! Can you hear me now? Cripes! Can you…?”
Follow-up e-mails are okay, and quite necessary during these times of overzealous spam filtering. But for the love of all things good and holy … please give your recipient a reasonable amount of time to answer the FIRST message FIRST!
If you haven’t waited *at least* 24 hours — particularly on a first contact — you haven’t waited long enough. People do have to take care of lives, and spouses, and hunger pangs, and bathing, and… (well okay, maybe not those last two if we’re in a REAL pinch ;)).

2. “NO, Mommy! I don’t WANNA read an ezine!”
It’s inconsiderate to send ezine length e-mails to business people — period.
You’re almost guaranteeing that your mail won’t be fully read, or that you’ll get a half-a**ed reply, because the reader didn’t feel like wading through your verbosity to get to the goods.
“Ezine length” is generally about 9 kilobytes (9k) and above. You can usually tell how large an e-mail is before sending by checking its size in your mail program’s outbox. If not, for your reference, 9k is about 650 words. (Yeesh!)
Unless the recipient is *expecting* a long reply from you, 3k (200 words) is a good stopping point for a first contact.
NOTE: YES, this goes for personal e-mails too. Being “friends” with someone isn’t license to consistently disrespect their time with mammoth e-mails unless they send the same to you — consistently.
So, no saying the same thing 8 killion different ways, or using “flowery” language and “pretty” mental pictures to get your point across.
Just say it, say something else and for Heaven’s sake … KEEP IT MOVING.

3. Umm, seriously … is it really THAT important?
Ugh. Do I really need to explain this one? People who mark ALL of their messages High Priority remind me of the little dude who cried wolf, if you know what I mean.
When I consistently see these from the same people all the time, I start ignoring the priority and answering them LAST in a mail check, just to spite ’em.
Granted, not everyone is as crazy as me and will do this. But at the very least, you’re still hurting your chances of getting a reply to *seriously* urgent messages quickly, by abusing priority markers.
I could go on. I won’t.