Log Message:
Update to 68.1.0

Changelog:
    new
    Offer to configure Exchange accounts for Office365. A third-party add-on is \ 
required for this account type. IMAP still exists as alternative.

    fixed
    Edit tag not working

    fixed
    Write window: "Insert > Characters and Symbols" not working

    fixed
    Moving/dragging messages from "Search Messages" result dialog not \ 
working

    fixed
    Command line -compose "attachment=" not working

    fixed
    Custom views not working

    fixed
    Issues with list of content types/actions for incoming attachments

    fixed
    "Learn More" links in Error Console not working

    fixed
    Visual glitches: Quick Filter Bar tag buttons too tall, missing scroll
      bar on Connection Setting subdialog, LDAP server selection after \ 
"New",
      "Edit" and "Delete"

    fixed
    Calendar: Parts of CalDAV dialog not working

    fixed
    Various security fixes

Security fixes:
CVE-2019-11739: Covert Content Attack on S/MIME encryption using a crafted \ 
multipart/alternative message
#CVE-2019-11746: Use-after-free while manipulating video
#CVE-2019-11744: XSS by breaking out of title and textarea elements using innerHTML
#CVE-2019-11742: Same-origin policy violation with SVG filters and canvas to \ 
steal cross-origin images
#CVE-2019-11752: Use-after-free while extracting a key value in IndexedDB
#CVE-2019-11743: Cross-origin access to unload event attributes
#CVE-2019-11740: Memory safety bugs fixed in Firefox 69, Firefox ESR 68.1, \ 
Firefox ESR 60.9, Thunderbird 68.1, and Thunderbird 60.9