Modifying Thunderbird's Reply Header

Mozilla Thunderbird is an email program which is feature rich, user friendly, and free. Brought to you by the Mozilla Foundation, it's an open source product that runs on Linux, Windows, and MacIntosh OS X. Configuring some of Thunderbird's more obscure features can be a bit tricky, or at least not obvious without some relevant documentation. Configuring the "reply header" is one of these.

What's a Reply Header?

When you reply to an email in Thunderbird, you can include the text of the email you're replying to. This is referred to as "quoting" and the text of the message you're replying to is called the "quote". After you click on the Reply button to open up a window in which to compose your reply, but before you even begin typing, the body of the message of the email to which you're replying will be automatically inserted into your Compose window. (If Thunderbird isn't doing this for you, go to Edit > Account Settings... > Composition & Addressing and check the box next to "Automatically quote the original message when replying".)

Say you want to reply to an email from your good friend Angelina Jolie. You've hit Reply and Thunderbird has opened the Compose window, and the text of the email you're replying to, the "quoted text", has been magically inserted. There'll also be a line like Angelina Jolie said: automatically generated and placed immediately above what Angelina Jolie wrote to you. This is the reply header. Personally, I like to have the date and time included in the reply header, as in

Angelina Jolie said on 10/09/2006 10:38 AM:

because it reminds me, and Angelina too, when she sent me her email. There's a thousand reasons why this is a good idea, most of which are based on the premise that good communication requires context. Unfortunately, including the date and time in the reply header isn't the default behavior for Thunderbird. Moreover, Thunderbird doesn't provide any documentation on how to configure it, nor is it at all intuitive to figure out. So in the interest of better communications, here's how it's done.

Accessing the Preferences

In the Thunderbird main window (or the Compose window), go to the "Edit" menu, select "Preferences" to open up the preferences window, click on the "Advanced" icon (the gear) top-right, and then, if necessary, on the "General" tab. In this view, click on the button which says "Config Editor...". This will bring up the "about:config" window. In the text box at the very top of it type in "reply" (without the quote marks). This will, in effect, do a search on all the preferences containing the word "reply" and therewith narrow down the number of items you'll have to scroll through to find the ones you'll need to change. Here's the preference items we'll need to concern ourselves with:

Preference Name		Value
mailnews.reply_header_type		3
mailnews.reply_header_authorwrote		%s wrote
mailnews.reply_header_ondate		on %s
mailnews.reply_header_separator
mailnews.reply_header_colon		:

For brevity's sake, a couple nonrelevant columns have been left out of the table above.

The values listed in the table above will probably be different from the ones you have. If you did have the same values as those above, your reply header would look something like this:

Angelina Jolie wrote on 10/09/2006 10:38 AM:

To make a change to a preference, right-click on it to bring up a small pop-up window. This little window will give some editing options: "Copy Name", "Copy Value", "New", "Modify", and perhaps "Reset". Click on "Modify". This will bring up another little window with text in an edit box containing that preference's current setting. Just edit it to look how you you want it to be.

For example, if you do the above to edit the Value for "mailnews.reply_header_authorwrote", it'll probably say "%s wrote" (without the quotes). If, instead of "Angelina Jolie wrote" you'd prefer that the reply header said "Angelina Jolie has written", then type in "%s has written", without the quotes but with the "%s" characters; these two characters are code for the sender, or more precisely, whatever is specified in the "From:" field of the email you are replying to.

Proceed in a similar way to make any other desired changes. For the mailnews.reply_header_ondate preference, again, the "%s" characters are code; in this preference they stand for the date and time. So be sure to include these two characters when you edit this value; "on %s" is an obvious candidate for this preference's value.

Though you might not be able to see it, the value of the mailnews.reply_header_separator preference is a space character. As you might guess, this value specifies the character(s) you want to be used to separate the two parts of the reply header just mentioned. Most people will use a single space character here, but it can be given other characters and more than one of them. Whatever other characters you might enter here, just be sure that the first and last of them is a space character. Otherwise you'll have words running together.

The final character(s) of the reply header will be whatever you specify for mailnews.reply_header_colon. By default it is the colon character (:). But if you wanted to express some creativity, you could set it to something else. For instance, set this preference to ", then wrote no more:" and your reply header will look like this:

Angelina Jolie wrote on 10/09/2006 10:38 AM, then wrote no more:

Last but not least, the value of mailnews.reply_header_type must be the number 3 if you want the sort of reply header shown above. If you enter a 2, then in your reply header the value in mailnews.reply_header_ondate will precede whatever you have for mailnews.reply_header_authorwrote. That is, your reply header will say, on 10/09/2006 10:38 AM Angelina Jolie wrote:. Perhaps this is precisely what you want. But if so, you will probably want to capitalize the first character in the date expression, i.e., make it On %s instead of on %s.

When you've finished making all your changes, click on the "X" in the upper right of the "about:config" window to close it. Your changes will be saved automatically and become effective immediately. Click on "Close" to close the "Thunderbird Preferences" window and return to the Thunderbird main window. Now you're ready to reply to an email and see your new reply header. Give it a try.

Fun and Danger

As you might imagine, you can do a lot with just these five variables and have a lot of fun with them. But remember that whatever reply header you set up will be included in every email reply you send. (Of course you can always edit the reply header for an individual email when it's in the Compose window, but you can forget to do this also.) Something with a comical flair that you might configure now might not seem comical at all to your boss or professor or teacher or someone you're trying to favorably impress. Someone not familiar with email might not understand that a reply header is automatically generated and so doesn't specifically refer to them. Moreover, if you have more than one email address set up in Thunderbird— perhaps one for work or school and another for personal use— the same reply header will be used for each. Thunderbird doesn't currently offer the ability to configure separate reply headers for different email addresses. While creating your reply header, keep all this in mind.

Finally, don't worry about messing things up or breaking Thunderbird so it doesn't work anymore. You can always go back to the small pop-up window mentioned above and click on "Reset" to put any preference value back the way it was before you started. You could even reset all of them and thus, in effect, start over again from the very beginning. The Mozilla folks made it so that anything you do here, whatever silly mistake you might make, can be easily fixed. So don't worry about a thing. Have at it and have fun.

© K e n F i s l e r, 2006. All rights reserved.