Although it would be good to know if there is some regular expression that can strip out the double-dashes in a footer, without also stripping out the double-dashes in people's messages.
My footer looks like this:
"--
list address: sm@simplelists.com
list archive:
http://archives.simplelists.com/smsubscribe, unsubscribe:
http://simplelists.com/subscribe/sm"
Does Nabble support multi-line regular expressions? If so, then a pattern that matches all 4 lines could be searched for and deleted.
Otherwise, I don't know of a regular expression that would be able to tell the difference between the double-dashes in this footer, and double-dashes in people's messages (maybe if I could specify that the double-dashes are the only non-whitespace on the line?)