This simple addon currently allows the user to add a sensitivity indicator ('Personal/Private/Company-Confidential') to an outgoing message via an option in the tools menu, or from an optional drop-down toolbar menu (similar to message priority). While adding this header does not directly add any security to the message, the header can be interpreted by some MTA/MUAs such that the message is treated differently while in transit, or when viewed by the recipient:
- e.g. MS Outlook/Exchange: Can be set so that confidential/personal messages are unable to be read by the recipient's delegated users; A warning can be displayed before the message is forwarded; Displays an advisory message above content.
- e.g. Some versions of Symantec PGP in corporate set-ups can automatically encrypt the outgoing message if leaving the corporate network, or redirect it to a secure corporate webmail page (with an automated notification email to the recipient to collect it there).
Please note that other MTA/MUA software (e.g. Popular webmail systems, Thunderbird without this add-on) may completely ignore the header as it is not commonly used outside of corporate environments. Therefore, please do not solely rely on it for ensuring your message is treated as intended.
- When re-opening a draft message where a sensitivity was set, the previous value is not currently retained.
- Similarly, when forwarding or replying to a message, the sensitivity value from the original message is not currently retained. As such, please make sure to select the correct sensitivity before sending your messages - if you add the toolbar item, this is always visible when composing. I hope to find a fix for these issues in a future version.
- This addon does not currently show an indicator for received messages yet - In future versions of this addon, I may add some kind of (optional) banner above the message when the header is set to Personal/Private/Confidential. In the meantime, if the header has been set on any message, it will be visible if 'View Menu -> Headers -> All' is ticked.
If you're familiar with Thunderbird addon development or can help with translations, and would like to help out, please get in touch.
- When editing a draft, or replying to a message with this header, make the header in the new message the same.
- Add the toolbar item automatically on install.
- Display an (optional) banner above received message (if header is set to priv/pers/conf).
- Automatically add the header to the searchable headers list. (and remove it on uninstall).
user_pref("mailnews.customHeaders", "Sensitivity");
Must ADD it to list of searchable message fields in case there are other fields there from other addons - Keep UI strings localised where possible.
- When the selected sensitivity is 'normal' when composing, remove the custom header completely.