Mozilla Thunderbird is a great free email client, but one thing about it has always bugged me: When you reply to a message, it puts something like “Scott Nellé wrote:” above the quoted text. Every other program I’ve ever used includes the date and time as well, which helps give context to the message. Unfortunately there’s no apparent way to change this from the options panel. But there is a way to do it. Here’s how:

1. Open the options panel. In Windows, go to Tools > Options… (For Mac OSX Thunderbird > Preferences…, for Linux Edit > Preferences…)
2. Click the Advanced tab and then the Config Editor button.
3. Find the preference named “mailnews.reply_header_type” and change its value to 2 (it’s probably set to 1 by default.)

Your replies should now show something like “On 2/28/2008 9:25 AM, Scott Nellé wrote:” above the text you’re responding to. Sweet.

Check Mozilla’s site for more info about reply header options in Thunderbird. Though that section mentions editing user.js, you should be able to make most changes in the config editor as mentioned above.