I use Icedove/Thunderbird on Debian together with TorBirdy. And it works very well. Now I created a new keypair and uploaded it to a keyserver and asked myself if TorBirdy is taking care of this connection also. Does anyone know?
The keyserver TorBirdy is configured to use by default is a Tor Hidden Service, so yes. In the event you alter the default keyserver to a different one, the answer is also yes. Documentation for TorBirdy is here: https://trac.torproject.org/projects/tor/wiki/torbirdy