my $smtp = '167.206.5.250';

# part 1, connect to server:
use Socket;
my $proto = (getprotobyname('tcp'))[2];
my $port  = (getservbyname('smtp', 'tcp'))[2];
my $smtpaddr = pack('C4',$1,$2,$3,$4) if ( $smtp =~ /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/ );
socket(S, AF_INET, SOCK_STREAM, $proto) or die("socket failed: $!");
connect(S, pack('Sna4x8', AF_INET, $port, $smtpaddr)) or die("connect failed: $!");;

# part 2, read first line:
local($oldfh) = select(S); $| = 1; select($oldfh);
while (my $line = <S>)
{
    print "--> $line\n";
    last;
}