format-patch --cc and send-mail --s-o-b-cc don't play nice together

Hi,

the --cc option from format-patch adds a Cc: header to the mail where
multiple recipients are put into a new line, separated by commas.
Unfortunately send-mail with the --signed-off-by-cc option can't parse
these lines.

Any ideas how to solve this?

Regards
Bert Wesarg