Tak jsme to udělal podle tohoto návodu This is a bit of a hack, but it works great with the messaging menu. Much better than FireTray or any of those things, which don't really work in 11.04 anyhow.
1. Install wmctrl
2. Make a script called start_thunderbird_hidden.sh in ~/bin/ (you can of course change the name of the script and where you put it)
3. $ chmod +x ~/bin/start_thunderbird_hidden.sh
4. Make the contents of the script as follows:
#!/bin/bash
thunderbird &
while [[ $(wmctrl -l | grep Thunderbird) == "" ]]; do sleep 0.1; done
wmctrl -r Thunderbird -b add,skip_taskbar
wmctrl -k on
5. Go to Startup Applications -> add -> Command: ~/bin/start_thunderbird_hidden.sh ,ale zatím mám asi někde chybu zaseknu se na 3. u chmodu.Musí být script v adresáři bin nebo je to jedno, asi by mělo že?Když script spustím tak se thunderbird normálně otevře.