Installation dans Ubuntu par le dépôt Mozilla
From https://support.mozilla.org/en-US/kb/installing-thunderbird-linux
snap remove thunderbird thunderbird-locale-fr
dpkg --purge thunderbird thunderbird-locale-fr
install -d -m 0755 /etc/apt/keyrings
wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- | gpg --dearmor -o /etc/apt/keyrings/packages.mozilla.org.gpg
tee /etc/apt/sources.list.d/mozilla-thunderbird.sources > /dev/null << EOF
Types: deb
URIs: https://packages.mozilla.org/apt
Suites: thunderbird-deb
Components: main
Signed-By: /etc/apt/keyrings/packages.mozilla.org.gpg
EOF
tee /etc/apt/preferences.d/mozilla > /dev/null << EOF
Package: *
Pin: origin packages.mozilla.org
Pin-Priority: 1000
EOF
apt update
apt install thunderbird-esr
apt install thunderbird-esr-l10n-fr