Dear Maintainer,

the Birdtray package has a dependency on the Thunderbird package in Debian,
meaning that using the Birdtray package requires installing the Thunderbird
package as well. However, there are other ways a user might install
Thunderbird, notably the binary the binary distribution from thunderbird.net.
This does not prevent Birdtray from functioning, as it offers an option to
specify the paths to the Thunderbird profile directory and executable.
In this case, they probably do not desire to install an extra copy of
Thunderbird.

I believe it would make sense to have the Birdtray package *recommend*
Thunderbird instead of depending on it, so it is possible to not install the
Debian package of Thunderbird if using Birdtray with TB installed from
another source.

I am not familiar with Debian packaging so I do not know if this is a
desirable choice, but it seems reasonable to me.

I am reporting from Ubuntu focal, but have checked via packages.debian.org
that this applies to Debian sid. The information below and above describe the
modified version I've made of the package that simply removes the thunderbird
dependency from the control file.

Thanks for your consideration