>  When using httrack behind a proxy, sites with
> https protocol are not accessible. I've got 
> errors like :
> 'Error:  'Unable to get server's address' (-5) after 2
> retries at link <https://www.foobar.com/> (from
> primary/primary)'

HTTPS does not currenty work with a proxy, and will issue 
direct connections - this feature will be added in a fiture 
release.