I'm new to LinksSql (no perl or programming experience)

Just had LinksSql installed (first install by Gossamer Threads) tried to register new user (first user) - error occurred, message as below:

A fatal error has occured:

Unable to send email. Reason: Sendmail exited with an unknown exit status: 1 at /homepages/41/d73721280/htdocs/cgi-bin/links/admin/Links/User/Login.pm line 192.

Please enable debugging in setup for more details.

So I tried again with debug level set to 1, error again - lots more info

any help or advice
Colin Thompson