Thunderbird about:config Modifications

From Indie IT Wiki

Access The about:config Editor

In the following examples you will need to access Thunderbird's configuration page:

Linux: Edit --> Preferences --> Advanced --> General

Windows: Tools --> Options --> Advanced --> General

Apple: Thunderbird --> Preferences --> Advanced -->General

Click the 'Config Editor' button

On the 'Here be dragons!' page click the 'I'll be careful, I promise' button.

Altering The Config

To the right of 'Config name:' is the value to copy and paste in the 'about:config' 'Filter' bar.

To the right of 'Default:' is the original value.

To the right of 'Modified:' is the new value.

To modify a true/false config state double click on the Config name.


Extension Install Delay (All Versions)

Config name: security.dialog_enable_delay
Default: 500
Modified: 0

Double-click on the entry in the windows below the filter bard and change the 'Value' to 0 for disabling the delay or lower the value to decrease the wait time, the setting is in milliseconds.

Fetching Attachments In Chunks (All Versions)

If you have issues with corrupted attachments try altering the following.

Config name: mail.server.default.fetch_by_chunks
Default: True
Modified: False

Blocklist Pings

Config name: extensions.blocklist.enabled
Default: True
Modified: False

Found here.

Sending Mail In Background

When sending email a dialogue box appears that displays the progress, but it prevents the user from performing any other tasks until it finishes.

Config name: mailnews.sendInBackground
Default: False
Modified: True

If you use the PrintingTools this option can be configured within the addon.

Downloads Window From Appearing

Config name:
Default: True
Modified: False


Accept Google Calendar Invitations

This modification is dependant on the installation of the Provider for Google Calendar plugin.

Config name:
Default: false
Modified: true

Thanks to Google Groups.

Always Show Attachment Panel Expanded In Message Pane

Config name: mailnews.attachments.display.start_expanded
Default: false
Modified: true

Middle Button (Scroll Wheel) Paste


Config name: middlemouse.paste
Default: true
Modified: false


Config name: middlemouse.paste
Default: false
Modified: true


Excessive CPU Usage: 1

Config name: mail.db.idle_limit
Default: 300000
Modified: 30000000

Thanks to Ian Chard for this fix which was originally found here.

Excessive CPU Usage: 2

Config name: mail.db.max_open
Default: 30
Modified: 15

"15" is just an arbitrary figure, experiment with different figures and see what works for you.

Thanks to Mozillazine.

Failure Of MAC OS X Contacts (Address Book) Integration

This traces back to a value not being written to the configuration file after authentication Thunderbird in System Preferences | Security and Privacy |

Config name: ldap_2.servers.osx.description
Value: Mac OS X Address Book

Thanks to Metaparadigma, which while not the actual solution above pointed me in the correct direction.

This also works on Postbox


Number Of To: Address Lines Shown In Compose Window

Config name: mail.compose.addresswidget.numRowsShownDefault
Default: 3
Modified: 2