Someone found a workaround
sudo mkdir -p /usr/lib/x86_64-linux-gnu/xfce4/exo-1/
and sudo ln -s /usr/lib/i386-linux-gnu/xfce4/exo-1/exo-compose-mail-1 /usr/lib/x86_64-linux-gnu/xfce4/exo-1/
Someone found a workaround
sudo mkdir -p /usr/lib/ x86_64- linux-gnu/ xfce4/exo- 1/
and sudo ln -s /usr/lib/ i386-linux- gnu/xfce4/ exo-1/exo- compose- mail-1 /usr/lib/ x86_64- linux-gnu/ xfce4/exo- 1/