thunderbird unsollicitedly opens emails

[Humphrey van Polanen Petel]

Thunderbird opens emails without being told to do so.

None of the opened emails as seen on the attached screenshot were opened by me.

Of interest must be the fact that not more than those emails shown were opened.

It has happened to me before.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: thunderbird 1:68.10.0+build1-0ubuntu0.20.04.1
ProcVersionSignature: Ubuntu 5.8.0-43.49~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-43-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: humphrey 594959 F.... pulseaudio
BuildID: 20200629235513
CasperMD5CheckResult: skip
Channel: Unavailable
CurrentDesktop: ubuntu:GNOME
Date: Mon Feb 22 17:17:38 2021
DefaultProfileExtensions: extensions.sqlite corrupt or missing
DefaultProfileIncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
DefaultProfileLocales: extensions.sqlite corrupt or missing
DefaultProfilePrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/thunderbird/omni.ja:greprefs.js:1138
DefaultProfilePrefSources: prefs.js
DefaultProfileThemes: extensions.sqlite corrupt or missing
ExecutablePath: /usr/lib/thunderbird/thunderbird
ForcedLayersAccel: False
InstallationDate: Installed on 2021-01-14 (39 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
IpRoute:
 default via 192.168.0.1 dev eno1 proto dhcp metric 100
 default via 192.168.1.1 dev wlx001325ad55e1 proto dhcp metric 600
 169.254.0.0/16 dev wlx001325ad55e1 scope link metric 1000
 192.168.0.0/24 dev eno1 proto kernel scope link src 192.168.0.10 metric 100
 192.168.1.0/24 dev wlx001325ad55e1 proto kernel scope link src 192.168.1.103 metric 600
MostRecentCrashID: bp-d8ee9043-ef35-483e-8c89-c1b0d0181224
Profile1Extensions: extensions.sqlite corrupt or missing
Profile1IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
Profile1Locales: extensions.sqlite corrupt or missing
Profile1PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/thunderbird/omni.ja:greprefs.js:1138
Profile1PrefSources: prefs.js
Profile1Themes: extensions.sqlite corrupt or missing
Profiles:
 Profile1 - LastVersion=68.10.0/20200629235513
 Profile0 (Default) - LastVersion=68.10.0/20200629235513 (In use)
RunningIncompatibleAddons: False
SourcePackage: thunderbird
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/14/2020
dmi.bios.release: 2.48
dmi.bios.vendor: HP
dmi.bios.version: N01 Ver. 02.48
dmi.board.name: 8054
dmi.board.vendor: HP
dmi.board.version: KBC Version 05.39
dmi.chassis.type: 4
dmi.chassis.vendor: HP
dmi.ec.firmware.release: 5.57
dmi.modalias: dmi:bvnHP:bvrN01Ver.02.48:bd07/14/2020:br2.48:efr5.57:svnHP:pnHPEliteDesk800G2SFF:pvr:rvnHP:rn8054:rvrKBCVersion05.39:cvnHP:ct4:cvr:
dmi.product.family: 103C_53307F G=D
dmi.product.name: HP EliteDesk 800 G2 SFF
dmi.product.sku: L1G76AV
dmi.sys.vendor: HP