ftpsync mail tool?

I'm not sure if I have the correct dependencies for ftpsync to send 
email reports (mailutils and ssmtp). However when ftpsync finishes 
instead of emailing me status it fails with:
'mail: Unknown command: -s'

Again I'm unsure if this is a known issue or if the archvsync script set 
depends on a different package for mail? If its a undiscovered issue 
then I have a patch already to fix it.

Thanks,
Chris