From Fedora Project Wiki
Netiquette Guidelines
In this page, I'm going to post some of guidelines related to Email Netiquette based on RFC 1855.
Reply at the bottom
If you are sending a reply to a message or a posting be sure you summarize the original at the top of the message, or include just enough text of the original to give a context. This will make sure readers understand when they start to read your response. Since NetNews, especially, is proliferated by distributing the postings from one host to another, it is possible to see a response to a message before seeing the original. Giving context helps everyone. But do not include the entire original!
Watch out reply-to address
Be careful when you reply to messages or postings. Frequently replies are sent back to the address which originated the post - which in many cases is the address of a list or group! You may accidentally send a personal response to a great many people, embarrassing all involved. It's best to type in the address instead of relying on "reply."