Using the TBB port 9150 exclusively breaks Torbirdy with a regular Tor install.

Since version 0.1.1 Torbirdy uses port 9150, as used by the TBB. Port 9050 is still used by most other Tor installations, e.g. the Debian package provided by the Tor project. Using different ports allows to run a TBB next to a regular Tor install.

https://trac.torproject.org/projects/tor/wiki/torbirdy#SetupSteps mentions that one should

make sure Tor is running with default client settings (SocksPort is listening on 127.0.0.1:9150)

but ideally Torbirdy should also check the default default port 9050.

This will probably also be usefull, when #3948 (moved) is implemented and some newer TBBs use 9050 again.

Trac:
Username: schulze