Having recently switched from the Mozilla Suite to Firefox/Thunderbird, I was sorry to loose some aspects of the integration between browser and email. The one for which I could not find some existing add-on was the ability to show a visual indicator that new mail is ready (even if not automatically downloaded).
I know that Thunderbird shows a popup message when mail is ready. But the popup may be shown and not seen if I am away from my computer at the time. I also auto-hide my windows task bar so the tray icon is not always visible. Also, since I do not automatically download new messages, I am not always aware that new mail is waiting to be downloaded.
So Thunderbird Biff will provide a visual indicator of new Thunderbird mail availability in both Firefox and Thunderbird. Install this add-on in BOTH Firefox and Thunderbird as there are both client and server portions.
A new icon is added on the right side of the status bar in both applications. Tool tips are provided for both applications and in Firefox you may click the icon to start/show the default mail program (which I hope will be Thunderbird).
If Firefox is started prior to starting Thunderbird, this add-on will show an unplugged cable icon. When Thunderbird is running, you should see either a plain mail icon (indicates no new mail) or a mail icon with a green arrow (indicates new mail is waiting). In case of error, a "X" icon is shown. Details of the error may be seen if the application is started with the -console argument.
By default, the add-on polls to check for new mail every 10 seconds. You can change this by adding an integer preference called "thunderbirdbiff.intervalSeconds" and setting it to the desired interval (I use 20 seconds).
Requirements: