Participate but be polite
Members are encouraged to participate in any mailing list as long as they honor Open Source principles of respect to other members and to the project at hand. Rudeness is not acceptable. Be polite. Remember that for some members, English is not even the second language. This means that you should always read over what you write and what others write to make sure of tone and content.
Messages should be short and to the point
Long messages probably will not be read in their entirety. The basic rules are “think twice, post once”, and have consideration for your reader. Before posting a question, ask yourself if you really need to ask potentially hundreds of subscribers, or can you find the answer yourself, e.g., from the archives.
Check to see if someone has answered the question adequately.
If it has been answered and you don’t have anything significant to add, consider not replying.
Stay on topic
When the context of the message changes, be sure to change the subject line, or your mail may not be read by many subscribers.
Try not to post messages simultaneously to more than one list
Choose a mailing list and send your message to that list only. Indicate where you want discussions to take place, e.g., “Sorry for the cross post. Please respond on architecture-rules-dev@googlegroups.com.”
Replying
When replying to other people it is customary to intersperse your response with their questions, both so you can answer the actual question that was asked, and so everyone else has some idea what you are talking about. It is also customary to limit your quoting to the minimum possible to get your point across. Take the time to be considerate, remember those subscribers who have slow, expensive connections.
Format: Plaintext
Mail to an e-mail list should only be sent PLAIN ASCII text format. Turn off HTML, MIME Encoding and “quoted-printable”. See “Configure Mail Clients to Send Plain ASCII Text.”
Whitelisting
For people who are using “you cannot send me mail unless you are whitelisted” spam filters: if you subscribe to the architecture-rules mailing lists, you must whitelist the lists yourself. We will not reply to any “please jump through these hoops to be whitelisted” mails. Such messages will be treated as bounces, and you may be unsubscribed or ignored.
Format: Width
If you can, set your mail client to line wrap at 72 characters, the same as you would on a printed page. This keeps mail width uniform and easier to read. It also means your e-mail is more likely to get read.
A Signature should be no more than 4 - 6 lines
Large and elaborate signatures will only serve to distract people from your message.
Some links on netiquette:
These guidelines are straight from the openoffice.org guidelines.