Changed:Animation setting now allows On, Off, and System Default options (#6027)Modernized 'Fetching mail' account settings screen (#11040)Fixed:Modernized 'Composition defaults' screen (#10724)Application could crash due to memory exhaustion (#11153)Application could crash when rendering long messages (#11148)Inline images were shown as attachments instead of displaying in message (#10889)Server search results could disappear after loading (#9142)Links failed when trailing punctuation was incorrectly included in URLs (#11060)Android widget text scaled too large when system font size was increased (#7790)Cancelling the Thundermail OAuth process incorrectly redirects users to the "Redirecting to Thundermail" screen (#11043)Custom swipe actions were not restored from exported settings backups (#10621)Contributors:Thanks to: @coreycb, @dani-zilla, @frabera, @jim-daf, @kryoseu, @mohitsatr, @mvanhorn, @numericOverflow, @rafaeltonholo, @shamim-emon, @stephenking314, @untitaker, @varshilsoni, @wmontweNew Contributors:@jim-daf made their first contribution in #11030@numericOverflow made their first contribution in #11032@varshilsoni made their first contribution in #11081@untitaker made their first contribution in #10800Full Changelog: THUNDERBIRD_20_0b2...THUNDERBIRD_21_0b1