"There are four ways, and only four ways, in which we have contact
with the world. We are evaluated and classified by these four contacts:
what we do, how we look, what we say, and how we say it."

- Dale Carnegie (1888-1955) American Educator
When it comes to your business e-mail communications, you need to make an impression that can lend to the determination that you are a credible professional enterprise and someone that will be easy and a pleasure to do business with. You only have one chance to make a first impression and that opportunity is invaluable to building trust and confidence
For your consideration below are the issues business owners and their employees minimally need to be aware of in their day-to-day online communications so their business can thrive.

SUBJECT: Field: The SUBJECT: field is the window into your e-mail and can many times determine even if your e-mail will be opened. If this is your first contact with a customer based on their request through your site or otherwise, be sure to have a short SUBJECT: that indicates clearly what the topic of the e-mail is. Never be misleading in this regard! Typos, all caps or all small case can lend to the impression you may be spammer.
Level of Formality: Never assume a position of informality in your business e-mail. Only time and relationship building efforts can guide when you can informalize your business relationships and therefore your e-mail tone. Remember, people do business with people; not companies. One should communicate as if your e-mail is on your company letterhead at all times. This is your business's image you are branding!
Addressing: How do you address your new contacts? I would suggest initially that you assume the highest level of courtesy: Hello, Mr. Anderson, Dear Ms. Jones, Dr. Osborne, etc. Until your new contact states, "call me Andy" or "you can call me Diane". Keep it formal until it is clear the relationship dictates otherwise. You will also be able pick up clues by how your contacts approach you and their tone. Most business people do not mind being called by their first name, however, in a global economy that can be perceived as taking premature liberties in the relationship if used too soon.
TO:, From:, BCc, Cc fields can make or break you:
...In the TO: field make sure you have your contact's name formally typed. John B. Doe - not john b doe or JOHN B DOE.
...In the FROM: field make sure your have your full name formally typed. Example: Jane A. Jones. Not: jane a jones or JANE A JONES. The later two give the perception of lack of education or limited experience with technology. Always use your full name. By only including your first name or e-mail address you are giving the perception you may have something to hide or do not know the basics of configuring your e-mail program.
...BCc: use this field when e-mailing a group of contacts who do not personally know each other. By listing an arm's length list of e-mail addresses in the CC or TO fields of contacts who do not know each other or who have never met is conducive to publishing their e-mail address to strangers. With those you are forging partnerships with, visibly listing their e-mail address in with a group of strangers will make one wonder what other privacy issues you may not respect or understand.
...Cc: Use this field when there are a handful of associates involved in a discussion that requires all be on the same page. These business people know each other or have been introduced and have no problem having their e-mail address exposed to the parties involved. If you are not sure if a business associate would mind their address being made public, ask!
Formatting: Refrain from using formatting in your business communications. Unless you would type something in bold crimson letters on business letterhead, don't do it when e-mailing for commercial gain. With all the spam filtering going on today; the more formatting or embedded images that you include, the higher the chance that your e-mail could be blocked as spammy. Even something as simple as using a different font makes your e-mail's display contingent upon the recipient having that specific font on their system or it defaults to their designated default font. Keep in mind the recipient may not have their e-mail program configured in such a way as to display your formatting the way it appears on your system - if at all.
Attachments: How do you think your relationship with a potential new customer is enhanced when you send them that 10M Power Point presentation they didn't request and you fill up their inbox causing subsequent business correspondence to bounce as undeliverable? And, if they don't have Power Point they couldn't open the file anyway! Never assume your potential customers have the software you do to open any file you may arbitrarily send.
If you need to send a file over 500,000 in size, business courtesy dictates you ask the recipient first if it is O.K. to send a large file. Next, confirm they have the same software and version you do and what is the best time of day to sent it to them to ensure they are available to download the large file and keep their e-mail flowing. Never send large attachments without warning, on weekends or after business hours when the recipient may not be there to clear out their inbox and keep their e-mail flowing.
Using Previous e-mail for New Correspondence: If you want to give the perception of lazy, find a previous e-mail from the party you want to communicate with, hit reply and start typing about something completely irrelevant to the old e-mail's subject. Always start a new e-mail and add your contacts to your address book so you can add them to a new e-mail with one click.
Down Edit Your Replies: Don't just hit reply and start typing. Editing is a skill those you communicate with will appreciate as it lends to reflecting a respect for their time and clarity in your communications. Removing parts of the previous e-mail that no longer apply to your response including e-mail headers and signature files removes the clutter. In addition, by making the effort to reply point by point keeps the conversation on track with fewer misunderstandings.
Common Courtesy: Hello, Hi, Good Day, Thank You, Sincerely, Best Regards. All those intros and sign offs that are a staple of professional business communications should also be used in your business e-mail communications. Always have a salutation and sign off with every e-mail. Here again - think business letterhead.
Signature files: Keep your signature files to no more than 5-6 lines or you may be viewed as a bit egocentric. Limit your signature to your Web site link, company name, and slogan/offer or phone number. Include a link to your site where the recipient can get all your contact information from A-Z - that is what your site is for. Don't forget to include the "http://" when including your Web site address within e-mails and your signature file to ensure the URL is recognized as a clickable URL regardless of the user's software or platform.

There you have it! The above basics will certainly allow your business communications to rise above the majority who do not take the time to understand and master these issues. When forging new business relationships and solidifying established partnerships, the level of professionalism and courtesy you relay in your business e-mail communications will always gain clients over the competition that may be anemic, uninformed or just plain lazy in this area.
When it comes to business, regardless of mode of communication used, professionalism and courtesy never go out of style!

Author's Bio: 

About the Author:
Judith Kallos is an authoritative and good-humored Technology Muse who has played @ TheIStudio.com for over a decade. Check out her popular E-mail Etiquette Web Site, Blogs, Books and Free Tools @: NetManners.com.