I use the auth method also via Net::SMTP::SSL against yahoo mail instead of google mail and it returns 1 if the authentication has worked.
in reply to Getting Net::SMTP::SSL debug information
The odd part is that your SMTP status Code 235 indicates that the authentication has worked.
I guess you need to step in the debugger to see where the problem starts...
Maybe you mixed the Net and the MIME module:
is what I do...
my $smtp = Net::SMTP::SSL->new("", Debug=>1, Timeout=>20, Port=>465);
$smtp->auth('', "") or die "Error message: $smtp->message";