Education Project/Effort/Complete feature send active document as
This application is an effort to fix issue 57043 (send active document as ..)
As of now, OOo assumes your Mail application is Mail.app and passes the document via 'open -a' to it. There is a specified API (to be moved to the wiki) between the code in OOo running when this feature is used and a helper application senddoc located in the Content/MacOS directory of the bundle. This helper is currently a unix shell script and can be edited without having to recompile any binary of OOo.
Retrieve the users preferred mail application from the desktop settings
This mostly means extending the Mac OS X specific configuration backend in [gsl/]shell/source/backend/macbe to include the key of the preferred e-mail client, so it has to be done in C/C++.
Support for Thunderbird
Instead of the 'open -a' approach, one could try to get the default Unix way of passing attachments to Thunderbird to work on Mac OS X. The problem here is that thundbird-bin behaves differently when it is already running than if not. There already is some code in the senddoc script that tries to handle this, but it checks the existence of the original mozilla launch script (as Linux vendors tend to use different ones, which try to handle these differences internally).
So this task requires good unix shell script or apple script knowledge.
AppleScript instead of 'open -a'
As we have the option to provide senddoc as AppleScript on Mac OS X, we might even find a way to achieve the same functionality using AppleScript see here for an example for AppleMail. If we can get some AppleScript working with Mail.app and Thunderbird, this later can probably extended to Entourage or <add your favorite mail client here>.