Trac 0.12 displays plugin revision info in a Installed Plugins table on the /about page (you must have CONFIG_VIEW permission to see this info). See t:#8921.
The attached patch adds revision info to the content of the macro and adds svn revision keywords to the .py file.
See #6391 for screen capture of new Installed Plugins section on the About page.
Also suggest renaming emailprocessor.py to EmailProcessor.py as this does not affect the functionality, but the filename is used in the Installed Plugins table so it looks and reads nicer.