XNote is a Thunderbird add-on that allows you to attach notes to individual e-mail messages. Initially released by StarXpert, it seems the original developers of XNote ended development of it. I ported XNote to Thunderbird 3 in December 2009 and sent them an e-mail containing the first version of the port, but did not get an answer. Consequently, I am currently maintaining XNote for Thunderbird 3.

Unfortunately, I don't have too much time to spend on this. If you run in troubles on Windows or Linux, you may report them in the hope that they might get fixed some time (better report patches ;-) ). Please verify that the issue is reproducible on a clean Thunderbird profile and include your operating system, XNote, and Thunderbird version number in the details. If you have troubles on a Mac, you are on your own if the issue is not reproducible on Windows or Linux as I have no access to that platform.

Testing with a clean/new Thunderbird profile: Create a new profile and check whether the issue is reproducible with the newly created profile. You don't have to migrate/configure all your data and accounts to the new profile. For testing it is usually sufficient to just copy the old "Mail/Local Folders/Inbox" file to the new profile while Thunderbird is closed, delete the corresponding Inbox.msf file of the new profile, and start Thunderbird to see whether your issue is reproducible.

Download: Please download from the Mozilla Add-on Website.

Please note that I did this port to TB3, because I am an XNote user. Consequently, XNote is currently in a maintenance phase and new features will primarily be added if someone is willing to contribute the necessary code. If you are interested in actively developing XNote, send me an e-mail. This add-on needs an active long-term maintainer.

However, this section lists some issues gathered so far along with some comments or workarounds.

• Question: I cannot see the XNote column with the icon indicating an attached note.
  Solution: You have to add that column manually via a (left-)click on the rightmost icon in the column headers of the e-mail list (above the scrollbar).
• Question: How can I get enable message highlighting for e-mails with attached notes?
  Solution: Use the advanced configuration editor (Tools – Options – Advanced – General – Config Editor...) to set the property "xnote.usetag" to "true".
• Some users report that notes hide behind the TB window.
  Comment: I cannot reproduce this. According to user feedback this seems to be a Mac-only issue. It could be be solved by using a separate place for notes within the TB window, e.g., similar to slide comments in Powerpoint. For now it may help to place the notes window beside the Thunderbird window without overlapping it. Another reported workaround is to select the note for editing via the context menu of the mail list or the toolbar button.
• Question: Could you store the notes directly in the e-mail so that the notes can be used across different computers when using IMAP?
  
  • Starting with version 2.2.1, you can configure the storage path for your notes. By default, notes are stored in the "XNote" folder in your Thunderbird profile directory. In order to access the notes on a different computer or to share them with other users, configure the storage path to a mounted network drive, e.g., using WebDAV, Windows Share / Samba, or NFS. Beware that this might have a negative impact on the performance of the message list (scrolling) due to the network latency and the way how the XNote column is implemented. Another solution is to save the notes in a Dropbox folder.
    In order to change the storage location, use the advanced configuration editor (Tools – Options – Advanced – General – Config Editor...) to add the property "xnote.storage_path" (right mouse click – "New → String") and configure it with your desired path. If you already had some notes, don't forget to move them to the new location.
  • Similar to the previous option, you can store your whole Thunderbird profile on a shared network drive (requires appropriate configuration of "profiles.ini" in your Thunderbird user directory). Beware that this might have a big performance impact – depending on your network and the amount of data stored in your profile directory.
  • Another suggested option is to use some custom X-... header to store the note in the message header (it was reported that MailTags for Apple Mail does that). This will most likely not be implemented—unless someone contributes the necessary code.
• Question: Could you make the notes searchable?
  Comment: In principle, this would be possible, although currently not practicable – anyone willing to contribute this? If you are in urgent need for this, open your Thunderbird profile directory, look for the folder called "XNote" and use a simple file search to look for the file containing the text. The notes can be viewed in a text editor. If you want to see the corresponding message, use the Thunderbird e-mail search to search, select "Customize..." to add a "Message-ID" header and search within this field for the message ID – the file name of the note without the ".xnote" extension.
• Question: After I activate the tagging feature by setting xnote.usetag to true, the messages with attached notes don't have the XNote tag assigned.
  Answer: Changing this parameter does not automatically lead to an update of all your messages (could take quite some time anyway). The XNote tag is only assigned when opening a message with a note or creating a new note. To just search all messages containing a note, sort by the XNote column
• Issue: If you upgrade XNote from some version < 2.1.0 to some version >= 2.1.0, your notes will miss the first 32 characters. The reason is that the original XNote developers changed the storage format with version 2.1.0.
  
  Solution: Please note that I provide the following without any warranties.
  
  You may try a small converter I've written for that issue. It requires that you have Java installed. Save XNoteConverter.jar to your computer and double click on the file from the file manager. If this does not work, open a command line window, change to the directory where you stored XNoteConverter.jar and call "java -jar XNoteConverter.jar". This brings up a file chooser in which you select the XNote directory located in your Thunderbird profile directory. This XNote directory contains files with a ".xnote" extension. Before you confirm the dialog, make a backup copy of that directory. After you made the backup, confirm the directory in the file chooser. Thereafter, the notes will be converted to the new file format as required for versions >= 2.1.0. The converter will also backup each existing note file by renaming it to ".xnote.sav" before the new converted note file is written. If you verified that the conversion worked correctly, you can delete all files with a ".sav" extension in the XNote directory.
  
  If you don't trust the compiled file, you may compile yourself from the source (if that is an option for you).
• Issue: If you resize the note so that the marker for resizing at the bottom right corner disappears, you can no longer resize the note after you released the mouse button.
  Comment: To reset the notes window to the default size and position, right-click on the mail in the message list and select "XNote – Reset note window".
• Issue: If you minimize Thunderbird to the system tray by using the MinimizeToTray Plus extension while an XNote window shows a message, the XNote window is not closed. If you close the XNote window, the Thunderbird window will be restored and you have to minimize it again.
  Comment and workaround: This is a minor incompatibility with another add-on. MinimizeToTray only minimizes the main window, but not other windows with messages or the XNote window. In order to work around this issue, close the XNote window or select an e-mail without an associated note before you minimize to tray.
• Issue: If an e-mail is moved to the Trash folder and is then deleted, the old XNote file remains on the disk.
  Workaround: Delete the XNote before deleting an e-mail.
• Issue: If an XNote is added to a draft e-mail, the note disappears after sending the e-mail.
  Comment and workaround: Unfortunately, Thunderbird changes the Message-ID at the time it sends the message. This has the effect that the note is still there, but the association of the message to the XNote file is broken. The manual fix for this issue is to copy the content of the note, delete the note, send the message, create a new note for the sent message, and paste the copied content.
  If you already sent the note, you can manually rename the notes file (located in the XNote directory of your Thunderbird profile directory – unless you changed it). For this you have to identify the note via the date of the last change and inspecting the notes file or searching for some known content within the files. If you identified the file, change its filename to the correct message ID. To find out the message ID, select the sent message, select "View – Message Source" from the menu, and lookup the Message-ID header.
• Issue: If you use a theme like PitchDark with white text, the text on the yellow notes becomes unreadable.
  Solution (posted by Cocinero in the XNote reviews): Add the following to your userChrome.css file (in the chrome directory within the TB's profile directory – create file and folder if necessary):
  /* XNote: set text color to black */
  .boite-de-texte, #titre {
  color: black !important;
  }
  → This will set all text in the notes boxes to black.
• Question: Is it possible to change the font size of the notes?
  Solution: Similar to the solution above, you can specify a font size in userChrome.css:
  /* XNote: set font size to 12pt */
  .boite-de-texte, #titre {
  font-size: 12pt !important;
  }

Below follows a collection of further feature requests/open issues, without comments:

• Hotkey for adding notes.
• Configuration of the initial XNote screen position
• Notes are shown if you select an e-mail with a note in the message list or open it in a new tab, but the note is not shown for e-mails opened in a new window.
• When you are on a message with an XNote and then switch to the Lightening calendar or the addons tab, the XNote window stays open.
• Notes could be smaller by default, dynamically expanding to the configured size when clicking into the note.

xnote-2.2.7 (Oct. 04, 2011)

• Italian translation updated
• Date in note window only updated upon text modification.

xnote-2.2.6 (Jul. 07, 2011)

• Japanese translation added.

xnote-2.2.5 (Mar. 29, 2011)

• Bugfix in French translation.

xnote-2.2.4 (Mar. 15, 2011)

• New configuration option that allows to select whether notes are shown by default after message selection.
• XNote can now be configured to show the first X characters in the XNote column.

xnote-2.2.3 (Nov. 15, 2010)

• Options dialog added.
• Galician translation added.
• Default date format changed to an international format.
• Dutch, French, and German translations updated.

xnote-2.2.2 (Oct. 28, 2010)

• Enabled XNote for Seamonkey 2.0.*
• Fixed the issue that the XNote toolbar button was not added automatically. This seems to be broken since the XNote version for Thunderbird 2.
• The column icon in the message header list is now the same as the XNote indication of the individual messages (yellow instead of gray).
• nl-NL and fr-FR translations updated.
• Some minor bugfixes

xnote-2.2.1 (Sept. 14, 2010)

• Notes storage path can now be configured via the xnote.storage_path preference (see FAQ).
• MessageIDs that are invalid filenames are now escaped – it was not possible to add notes to these messages as they could not be stored.
• French translation updated.

xnote-2.2.0 (Aug 25, 2010)

This is functionally equivalent to the 2.2.0pre2 version with minor changes:

• The XNote column is now called "XNote" instead of "Note".
• Icon available in the Add-ons manager.

xnote-2.2.0pre2 (Aug 16, 2010)

• Addressing Mozilla editor review comments in order to get this add-on out of the sandbox.
• XNote window is now aligned in relation to TB Window instead of screen and moves with the main window.
• Added context menu item to reset size and position of the XNote window.

xnote-2.2.0pre1 (Feb 14, 2010)

• Major version number change to indicate the TB3 update and the break with TB2. This should become the final 2.2.0 if no major issues occur
• Fixed the issue that notes could be added via right-mouse click only to the currently selected message
• Fix for adding XNotes via right click in the message pane.
• Fixed column handler – sorting works now.
• Fix for virtual folders (saved searches): Colum icon now displayed correctly for saved searches with multiple search folders.

xnote-2.1.1b2 (Jan 25, 2010)

This is the version moved to the Mozilla Add-ons website. See version xnote-2.1.1b.lf below for detailed comments as they contain the same code.

xnote-2.1.1b.lf (Jan 13, 2010)

Changes

• Fixed the annoying bug of the previous version that notes are lost if you immediately close Thunderbird after editing a note. There were some more things to do than just API compatibilities in the change to TB3.

Known (and reproduced) issues

• If you right-click on the message pane (the place where the e-mail content is shown) and select "XNote --> Create note", the notes window is not shown.
  Workaround: Use the toolbar button (or right click in the message list) to add new notes.
• The XNote context menu is only enabled if you right-click on the currently opened message in the message list. If you right-click on a different message, the menu is disabled.

xnote-2.1.0-lf (Dec 12, 2009)

• Straight forward port from TB2 to TB3 based on fixing API incompatibilities.

Known (and reproduced) issues

• If you change (edit, resize, move, etc.) a note and then immediately close Thunderbird, you will lose the edited note.
  Workaround: Change to a different mail message before you close Thunderbird.