The -m option in Red Hat patched version of enscript 1.6.1-25 takes an argument (mandatory, of course), while the --mail option has optional argument. This is incompatible with the original GNU enscript. And I think that it may be confusing. It would be perhaps preferable to create a new long option to specify the alternate email. In any case, the change is not documented in the manpage nor in the help.
Actually since CUPS's lpr doesn't even support -m, I can probably just take that patch out altogether.
Sticking to the original source is always good. And if there is no big demand to have the feature... (Thanks for prompt reply, Tim!) --Stepan Kasal
Removed in CVS.