How to use --cc-cmd in git-send-email?

I've been using git-send-email with repeated individual --cc="email address" parameters on the command line.

I tried putting all the addresses, one per line, into a file 'cc-cmd', so I could use if for the --cc-cmd option.

I then tried to use --cc-cmd='cat cc-cmd' to do the send-email (as a --dry-run). This produced, as part of the output, a list of the output of the cc-cmd, which showed not only the file contents, but this was then followed by the full patch, as if it was part of the list of email addresses.

Finally, at the end of the inclusion of the patch, I got

(cc-cmd) Adding cc: -- from: 'cat cc-cmd' (cc-cmd) Adding cc: 2.4.2.windows.1.5.gd32afb6 from: 'cat cc-cmd' (cc-cmd) Adding cc: from: 'cat cc-cmd' error: unable to extract a valid address from: What to do with this address? ([q]uit|[d]rop|[e]dit):

Could this have been caused by an extra (blank) line at the end of the cc-cmd file?

Also, does anyone have an example of a working --cc-cmd option?

(this is on g4w: git version 2.3.1)

Philip