Receiving E-mail Etiquette

Replying to E-mail: Don't reply to "all recipients" unless they all need your reply. Verify the recipients before mailing the message. Before sending a message, read it over, and double-check the recipient(s). Each recipient of your e-mail message will see only his or her name at the top of the e-mail message. Do not send replies to all recipients unless there is a very specific need for everyone to receive the message. It wastes disk space, clutters up in-boxes and annoys people.
Out-Of-Office: As a consideration of prompt reply, it’s a good idea to setup an ‘out of office’ reply to those who might try to reach when you are on leave. You can setup a message to let the recipient know how long you will on leave and who to contact temporarily while you are away.
Forwarding: Get the author’s permission first - when forwarding an e-mail message that someone else has written, whether the writer is an employee, client or partner. If that’s not possible, restate the original contents in your own words, noting the source of the information. Never paste someone else’s text into a message and send it off as if you’ve written it.
Replying to All:    Look at the recipient list before you hit Send. Think about whether you really need to copy all those people on your reply; if you don’t, delete the extra addresses before sending the message.