Most of the world’s email traffic comes from the corporate sector, according to technology market research firm The Radicati Group. Radicati Group’s recent email statistics report finds that so far in 2012, “the number of business emails sent and received per day total 89 billion.” How important are these emails? According to a separate report by cloud-based email management company Mimecast, 61% of emails received at professional email accounts are non-essential.

No wonder professionals often complain about the size of their inboxes — we’re all sending/receiving many emails daily, and only one in three emails received is viewed as essential for work.

Are you guilty of adding to your co-workers’ email clutter by sending spam and/or non-work related emails? Or possibly you send work-relevant emails that are misinterpreted as non-essential? Whatever the case, email is a major form of business communications — so if you want your emails to be read and regarded with credibility, be sure you are adhering to basic email etiquette.

Below are our top ten rules of business email etiquette. Which one resonates with you the most? Which email etiquette pointers should be added to the list?

1. Refrain from emotionally-charged emails
Avoid sending emails when you’re feeling any type of negative emotion, e.g., anger, irritation, frustration. Emotionally-charged emails almost always include words and phrases that will make you look unprofessional and irrational. Before you send off that email rant or reply to an email that angers you, try cooling off by taking a walk. Or, write an uncensored draft that you never actually send. Remember that all emails are forwardable, so before sending that incendiary email, ask yourself if you want your email to be viewed by everybody, including your supervisor and executives.

2. Make the email subject line count
The subject line is arguably the most prominent part of an email — the subject line can determine whether or not your email will be opened/read. Take the time to write a meaningful subject line, one that is brief and relevant to the content of your email. Be sure to correct misspellings and typos, which will make you look sloppy and vulnerable to spam filters.

3. Resist the Reply All button
When someone sends an email to multiple recipients, the assumption is that everybody on that thread is directly or peripherally involved in the particular subject matter. If you have additional data points and/or questions relevant to the subject matter, then the Reply All option is okay. However, if you have a comment/question relevant only to the sender or a few people on the recipient list, then remove all but the relevant people from the email reply. And if you have something completely meaningless to add, e.g., “LOL” or “me too!”, don’t even bother sending the email.

4. Understand the To and CC fields

The recipients listed in the To field are the direct addressees of your email. These are the people to whom you are writing directly.  CC, which stands for “carbon copy” or even “courtesy copy,” is for anyone you want to keep in the loop but are not addressing directly in the email. The person(s) in the CC field is being sent a copy of your email as an FYI. Commonly, people CC their supervisors to let them know an email has been sent/an action has been taken or to provide a record of communications. The general rule of thumb is that recipients in the To field are expected to reply or follow up to the email, while those in the CC field do not.

5. Call out additions to the To or CC fields
If you’re replying to an email and you add recipients to the thread (either in the To or CC field), be sure to call this out at the beginning of your email reply, e.g., “+1 Baochi” or “adding Baochi.” This is a courteous alert to your recipient(s) that additional people have been added to the conversation.

6. Use the BCC field sparingly
BCC stands for “blind carbon copy.” Recipients in this field cannot see one another’s email addresses. Use it primarily for sending an email to multiple recipients who don’t know one another (note: if you are introducing recipients to one another, then use the To field so everybody’s email is visible). Don’t use the BCC field to secretly loop in additional, unknown recipients.

7. Limit back and forth exchanges
If you find yourself in a back and forth email exchange, make an effort to talk in person instead. While email is a powerful communications tool, it can be misinterpreted and downright inefficient. Resolve the back and forth emails by picking up the phone or meeting with the recipient in person.

8. Zip up and reference those attachments
Most corporate email accounts have a maximum message size that prevents recipients from downloading files that are too big. If you’re sending attachments over 5MBs, use compression tools to decrease the size of the files. For more information on how to compress email attachments, read this article. Also, remember to reference the attachment(s) in the body of  your email so readers know to download the file(s).

9. Emailing an article link? Summarize
If you’re recommending that your colleagues read an article you email to them, be sure to provide some context. Be sure your email subject line indicates you’re sending an article, and include the article’s title or topic matter, e.g., Article: Email Etiquette. In the body of the email, provide a short summary — from as brief as a one-sentence description to a more detailed one with bullet points.

10. Keep it brief
We’re all guilty of sending lengthy emails. And it’s true that now and then, lengthy emails are appropriate. But for the most part, we should all keep it brief. Long emails take more time to read — and everybody is pressed for time. Most people delay reading long emails. It’s easier to consume smaller bits of information, especially on mobile devices. So make your emails count, and keep them brief!