For general information, before you ask on a list, start with colleagues, the library, standard textbooks, and journals. Ask specific questions rather than general ones. Reply to messages only when you have something substantive to contribute. When possible, back your opinions with first-hand experience. With this in mind Send all substantive comments and responses to the entire group.
Subject lines are also useful when searching list archives.
As a courtesy to colleagues, ensure that the subject line of your message clearly reflects the content. Sending attachments to lists is inappropriate. Many international subscribers will have ISPs that cannot receive attachments. Many subscribers are novices who cannot handle attachments. Never send attachments to mailing lists.