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Thunderbird Preferences Relevant to Enterprises

Preferences related to use of Thunderbird in enterprises

Account Provisioning

New in Thunderbird 13

Account Provisioning allows users to sign up for new email accounts directly from within Thunderbird.

  • mail.provider.enabled
    • Default: true
    • Default Action: If the user does not have an account set up, they will be prompted to sign up for a new account. They may choose to set up an existing account that they hold instead of obtaining a new one.

New in Thunderbird 13

Filelink is a feature that allows users to upload big files to various servers and send a link to the attachment in the email, rather than the attachment itself. This has benefits for sending the email, especially when sending to multiple users.

It is possible for other providers/accounts types to be set up; we are working on documenting that at the moment.

  • mail.cloud_files.enabled
    • Default: true
    • Default Action: Prompts the user to see if they wish to send a link for big file attachments, rather than the link itself

Instant Messaging

New in Thunderbird 13

Instant Messaging allows the user to access different types of messaging accounts, e.g. twitter, irc and general chat.

    • Default: true
    • Default Action: Enables access to the Instant Messaging user interface in Thunderbird
    • Notes:
      • Although all the UI options to access Instant Messaging itself are disabled, the preferences window still shows the Chat options, see bug 735347


By default all HTML elements are interpreted by the Thunderbird HTML parser.

  • Obsolete mailnews.display.html_sanitizer.allowed_tags
    • Default: html head title body p br div(lang,title) h1 h2 h3 h4 h5 h6 ul(type,compact) ol(type,compact,start) li(type,value) dl dt dd blockquote(type,cite) pre noscript noframes strong em sub sup span(lang,title) acronym(title) abbr(title) del(title,cite,datetime) ins(title,cite,datetime) q(cite) a(href,name,title) img(alt,title,longdesc,src) base(href) area(alt) applet(alt) object(alt) var samp dfn address kbd code cite s strike tt b i table(align) caption tr(align,valign) td(rowspan,colspan,align,valign) th(rowspan,colspan,align,valign) wbr
    • Default Action: Allows specified elements to be interpreted by Thunderbird's HTML parser
    • Notes: Obsolete after Thunderbird 13, use mailnews.display.html_sanitizer.drop_media and mailnews.display.html_sanitizer.drop_non_css_presentation instead. The preference will be automatically migrated to the new preferences if necessary.
  • New in Thunderbird 14 mailnews.display.html_sanitizer.drop_media
    • Default: false
    • Default Action: Allows all media files.
    • Notes: To restrict the <img> element from being interpreted (and thus prevent images from displaying in HTML messages), set to true.
  • New in Thunderbird 14
    • Default: true
    • Default Action: Drop non-CSS presentational HTML elements and attributes, such as <font>, <center> and bgcolor=""
    • Notes:

Version Upgrades

Select your Add-ons

  • New in Thunderbird 10 extensions.autoDisableScopes
    • Default: 15
    • Default Action: When upgrading to a build from before Thunderbird 10 to after, the user will be prompted about add-ons installed by Third Parties.
    • Notes: This preference is a bit-wise OR of values that control the locations for which add-ons are prompted about as third-parties. Organizations typically want to set this to 11 if they are installing thier own add-ons. The bit values are as follows:
      • 1: Installed in the profile
      • 2: Installed for all of this user's profile
      • 4: Installed and owned by the Application
      • 8: Installed for all users of the computer

Migration Assistant

    • Default: true
    • Default Action: Shows the migration assistant when we're upgrading a profile from 3.0 or earlier.

Offline Download / Synchronisation

  • mail.server.default.offline_download
    • Default: true
    • Default Action: Used to determine if newly created folders are set to take part in offline download or not.
    • Notes:
      • This is the default value for all servers/accounts, i.e. when the mail.server.server<n>.offline_download is not set.
  • mail.server.server<n>.offline_download
    • Default: true
    • Default Action: Used to determine if newly created folders are set to take part in offline download or not.
    • Notes:
      • This value is typically not present unless it has been specifically overridden.
      • Overrides mail.server.default.offline_download for server<n>

Both preferences now also have the behaviour that if offline_download is true for an account/server, then on upgrade from Thunderbird 2, all existing IMAP folders will be updated to take part in offline download.