Answer under the question: example

This article was first written in January 2004 for
the BeezNest technical website (http://glasnost.beeznest.org/articles/103)
You should always try to answer right under the question when replying to an e-mail. This is only to ensure maximum readability, which is the goal of what you write. Here is a (fake) short example: 1) No! 2) I've been there on holiday once.

Cover only one topic per e-mail and give a sensible subject

This article was first written in March 2005 for the BeezNest technical
website (http://glasnost.beeznest.org/articles/213).
Answering under the question should be the default. Similarly, and to avoid complicating answering to e-mails, try to cover only one topic (even huge) per e-mail. It will not cost you more to split your different subjects in several messages, and will allow you to give sensible subjects to your e-mails easily. In return, you can expect the answers to be more readable and finding something through all your e-mails far faster.