Beta Notes

OAuth2 authentication for Yahoo and AOL (already shipped in Thunderbird 60.0 ESR)

Calendar: Default values for the first day of the week and working days are now derived from the selected datetime formatting locale (restart after changing locale in the OS required)

Calendar: Switch to a Photon-style icon set for all platforms

Multiple requests for master password when Google Mail or Calendar OAuth2 is enabled

Scrolling the address entry auto-complete popup with the mouse wheel does not work (already shipped in Thunderbird 60.0 ESR)

Scrollbar of the address entry auto-complete popup does not work

Security info dialog in compose window does not show certificate status

Calendar: First day of the week cannot be set

Calendar: Several fixes related to cutting/deleting of events and email scheduling

When writing a message, a delete button now allows the removal of a recipient. This delete button is displayed when hovering the To/Cc/Bcc selector.

Further improvements to attachments handling during compose: "Attach" button moved to the right to be above the attachment pane. Alt+M now allows to show the attachment pane. The attachment pane can also be shown initially when composing a new message. Right-click on the header to enable this option. It is now also impossible to completely collapse a non-empty attachment pane. That protects against attachments accidentally being sent.

Thunderbird now allows the conversion of folders from mbox to maildir format and vice versa. This is an experimental feature that needs to be enabled by setting the preference mail.store_conversion_enabled. Note that this functionality does not not work if the option "Allow Windows Search/Spotlight to search messages" is selected.

Light and Dark themes

WebExtension themes are now enabled in Thunderbird

FIDO U2F support

Calendar: Allow copying, cutting or deleting of a selected occurrence or the entire series for recurring events

Calendar: Provide an option to display locations for events in calendar day and week views

Calendar: Provide the ability for sending/not sending meeting notifications directly instead of showing a popup

IMPORTANT: Add-ons not marked as compatible with Thunderbird 60 by their authors will be disabled (this can be reverted via preference extensions.strictCompatibility)

Thunderbird will now prompt to compact IMAP folders even if the account is online. Note: Under certain circumstances an incorrect estimate of the expected gain is shown.

Better address book photo handling: Photos can be added by drag and drop and a copy of all photos will be stored in the Thunderbird profile

Native notifications on Linux are now re-enabled

During address entry, the matching part of the address is now shown in bold. Preference mail.autoComplete.commentColumn allows to display the address book where the address is stored.

Calendar: Removal of capability to send email invitations compatible to Outlook 2002 and earlier

Various problems when forwarding messages inline: Some introduced in Thunderbird 60 beta 7, some dating back to 2005 when using "simple" HTML view.

The IMAP and News subscribe dialog did not present a folder tree (not working since Thunderbird version 59)

Messages moved between IMAP accounts were missing parts (embedded content or attachments) under some circumstances

Better error handling for Gmail authentication to avoid re-downloading of folders

Text in the address book card view wasn't selectable

UTF-7 support (not working since Thunderbird version 56)

Complete fix of the EFAIL vulnerability: 1) Removing some HTML crafted to carry out an attack. 2) Not decrypting subordinate message parts that otherwise might reveal decrypted content to the attacker. Preference mailnews.p7m_subparts_external controls this.

Thunderbird used a stale cached password after user edited a saved password

The new menu item "Add-on Options" introduced in Thunderbird 59 beta is now also working on Mac

Source view not working for JS, XML, CSS, etc. source files via 'Developer Tools > Error Console'. Other options: 1) Set preference view_source.editor.external and view_source.editor.path to view the source in the editor of your choice. 2) Use 'Developer Tools > Developer Toolbox, Console'. (not working in earlier versions of Thunderbird 60 beta)

Deleting or detaching attachments corrupted messages under certain circumstances (not working in earlier versions of Thunderbird 60 beta)

Calendar: Google account credentials not retained by Lightning

Provider for Google Calendar not available

CalDav access to some servers not working. Workaround: Set preference network.cookie.same-site.enabled to false.