Netiquette guidelines are recommendations of good practices for e-mail and mailing lists for efficient communication. They are mostly taken from RFC1855, which has general approval from the Internet community.

For mail

 Mail should have a subject which reflects the content of the message.

 Messages over 100 lines is considered "long". Be brief without being overly terse.

 Use mixed case. UPPER CASE LOOKS AS IF YOU’RE SHOUTING.

 Use symbols for emphasis. That *is* what I meant. Use underscores for _underlining_. Avoid colours, bold and italic, many people use mail readers that do not show them.

 Check the quality of your writing. Spelling and grammar will influence the recipient’s perception.

 Use smileys to indicate tone of voice, but use them sparingly. :-) is an example of a smiley (Look sideways). Don’t assume that the inclusion of a smiley will make the recipient happy.

 Remember that the recipient is a human being whose culture, language, and humour have different points of reference from your own. Be especially careful with sarcasm.

 "Reasonable" conduct via e-mail depends on your relationship to a person and the context of the communication. Be careful with slang or local acronyms.

 Assume that all mail on the Internet is not private. Never put in a mail message anything you would not put on a postcard.

 If you are forwarding or re-posting a message you’ve received, do not change the wording. If the message was a personal message to you and you are re-posting to a mailing list, you should ask permission first. You may shorten the message and quote only relevant parts, but be sure you give proper attribution.

 Be conservative in what you send and liberal in what you receive. You should not send heated messages (we call these "flames") even if you are provoked. Wait overnight to send emotional responses to messages.

 Be careful when addressing mail. There are addresses which may go to a group but the address looks like it is just one person. Know to whom you are sending.

 If you think the importance of a message justifies it, immediately reply briefly to an e-mail message to let the sender know you got it, even if you will send a longer reply later.

 Make things easy for the recipient. Include one to four lines at the end of your message with contact information. This is known as a “signature” file. Your signature file takes the place of your business card.

 Avoid sending large documents (more than 50 K). If you want to send an MS Word file, consider sending only the text from the document directly in your e-mail. RTF documents are also generally smaller and more compatible for people who do not have the latest Microsoft software.

For mailing-lists

In addition to the above recommendations:

 Consider that a large audience will see your posts. Take care in what you write. Mailing lists are frequently archived and your words may be stored for a very long time in a public place that people can accidently find via search engines such as Google.

 Be careful when you reply to messages. You may accidentally send a personal response to a great many people, embarrassing all involved. If you find a personal message has gone to a list, send an apology to the person and to the list.

 If you should find yourself in a disagreement with one person, make your responses to each other via mail rather than continue to send messages to the list. If you are debating a point on which the people on the list might have some interest, you may summarise for them later.

 Avoid sending messages which are no more than gratuitous replies to replies. If you need to send only a thank you note to someone, better to do it in private and not on the list. Ask yourself wether all the members on the list really need to know.