# Features
- The folder pane now shows a popup over folders with unseen messages.
- Sync can now open links received from other devices in tabs.
# Fixes
- Manual zoom reduction (85%) did not hold and returned to 100% with routine navigation within a website.
- MDN (return receipts) now work for non-standard headers and the MDN confirmation message now says which addresses the receipt will be sent to.
- Redirecting and error visits are now properly handled, i.e. not added to global history.
- The address book white list is now disabled in Junk Settings if adaptive junk mail control is not activated.
- Address books in text format (text, CSV, tab) which contain non-ASCII display names and email addresses can now be imported properly.
- Percent encodings on non-ASCII filenames are now decoded when saving a video snapshot.
- A Preferences pane for Offline Applications has been added.
- A click-to-play plugins option has been added to Preferences.
- The wording of the Disk Space compacting option has been enhanced (auto compact does all folders at once) and the compact limit field is now disabled together with compacting.
- A Layout sub menu has been added to the address book View menu.
- The vertical space between actions on the MailNews Account Central page is now flexible.
- Feed pages displayed in MailNews now support click-to-play plugins.
- Enhanced support for feed enclosures: Support for more than one enclosure per message, Atom support, media:content support.
- It could happen that MailNews account keys were reused in the same profile, leading to mails showing the wrong account in the Account column.
- TCP/SSL handshakes are now overlapped with typing in the search box, improving responsiveness.
- Ampersands did not appear in the Windows biff icon tooltip.
- The Outlook Express address book can now be imported from a non-default location.
- Temporary files created by mail composition did not get cleaned up correctly, leading to inability to add images inline.
- Scrolling/switching to IMAP folders could lead to short hangs.
- Multipart messages were downloaded entirely for each of their parts.
- Attachments were sometimes not fully downloaded due to incorrect/smaller RFC822.SIZE set by MS Exchange, GMail and possibly others.
- A DSN (Delivery Status Notification) option has been added to the Compose Options menu.
- HTML5 form validation errors are now shown as tooltips.
- The context menu handled OGG audio as OGV video.
- The Bookmarks Manager had lost its window icons.
- An animation is now shown when opening document-like windows on Mac OS X 10.7 Lion.
- Extensions may now send messages to mailing list recipients via BCC.
- Address book contacts now include an "Always prefer display name over message header" option.
- The option when clicking a mail address that is already in the address book now reads "Edit Contact" instead of "Add to Address Book".
- When importing an address book as CSV, the dialog description pushed all buttons off screen.
- Messages with undefined content type were incorrectly forwarded as attachment.
- The List all Tabs menu now shows tabs that scrolled off screen in italics.