Here are a few tips and tricks about how to get the best results from your email communications:
Keep your emails short. 1-2 lines are best, or 3 sentences. Preferably it would fit in a tweet. If you need to write a long email, think first whether the information wouldn't be better placed somewhere more permanent, e.g. a code comment section, a github repository README, a wiki entry, a Word document saved in Dropbox.
Acknowledge receipt. At least answer "Ok", "Noted", "Will do", "Sure" or something like that. It takes 2 seconds to do that, and it lets the sender know that you are on top of things.
Answer quickly. It's not 1990 any more, everything is faster now.
Use cc: freely. Keep everyone informed. Communication is really important in a company: copy as many relevant people as possible.
Don't blindly Reply-to-All. For example if you're sending a "Noted" acknowledgement, no need to reply-to-all - just reply to the person who sent the email.
Don't use bcc: It leads to too many pitfalls. For example a person you bcc:ed to might hit Reply-to-All, then all of a sudden all recipients become aware that you used bcc:, which can be embarrassing.
No dears. You can address people outside of the company with "Dear", but there's no need to do that for internal emails to colleagues.
Don't address with Mr or Mrs - it's too formal. It makes the recipient put up his/her guard and wonder if there are any legal aspects to the email!
Say please. You'll get a better chance of a response from "Could you send me your proposal please" than "Could you send me your proposal" without the please.
Give a reason. Studies have shown that its easier to jump a queue if you say "Please let me go first because I'm in a hurry" than just saying "Please let me go first".
Ask questions. You'll get a better chance of a response from "Could you send me your proposal please?" than from the same sentence without the question mark.
Careful with cut & paste in gmail - learn to use the "remove formatting" function, to avoid your email having unsightly formatting changes.
Make the subject appropriate - change the subject to something meaningful, even if you are replying to a thread.
Your inbox is a todo list - once you've processed an email, move it into a folder. Keep your inbox as clean and small as possible.
Learn to use labels in gmail and learn how to set label colours. It helps you keep things organised.
Drop the legalese disclaimers. They have no legal power, and they just clutter up email threads.
Use emoticons if you like when emailing colleagues, but don't do it with third parties.
Check your spelling and grammar - gmail underlines the mistakes, so there's no reason not to notice them.
Don't complain over email. Praise in writing, complain orally.
For internal communications within the office, prefer face to face - just walk over to someone and talk to them, rather than emailing them.
For internal communications between remote offices, prefer Slack - you'll get faster responses from your colleagues if you reach out to them over Slack rather than email. Slack encourages concision, rapid responses, maintains context, and helps build a rapport between colleagues.
For external communications, prefer the telephone - you'll get better responses and will build relationships.