Log Message:
Update to 45.3.0

Changelog:
    Fixed Certain messages caused corruption of the drafts summary database.
    Fixed "edit as new message" on a received message pre-filled the \ 
sender as the composing identity.
    Fixed Disposition-Notification-To could not be used in mail.compose.other.header
    Fixed Various security fixes

Fixed in Thunderbird 45.3
    2016-62 Miscellaneous memory safety hazards (rv:48.0 / rv:45.3)