use IO::Socket::INET;
use IO::Select;

my $addr = 'XX.XX.XX.XX';#mail server ip address
my $hostname = `hostname`;
#set our timeout to 30 sec
my $timeout = 30;
my $endtime = time + $timeout;

my $line;
my $socket;
eval {
	# get a connection to the ip
	$socket = IO::Socket::INET->new(
		PeerAddr => inet_ntoa($addr),
		PeerPort => 25,
		Timeout  => $timeout,
		Proto    => 'tcp', 
	);
};

# show message if we couldn't connect
$ipHash{'Message'} = 'Connection refused' unless $socket;  # connection refused
# get a select object & add our socket so we can do read timeouts
my $sel = IO::Select->new($socket);

#make sure we got a 220 initially
my $hello;
while ( time < $endtime && ! $@ ) {
	unless ($sel->can_read( $endtime-time )) {
		# returns time out
		$ipHash{'Message'} .= '<br>Connection timed out';
		last;
	}
	
	my $bytes = $socket->sysread( $line, 4096, length($line) ); 

	if ($line !~ /^220/m && $line) {
		$ipHash{'Message'} .= "<br>Connection error: $line";
		last;
	} else {
		$hello = 1;
		$ipHash{'Message'} .= "<br>Able to connect successfully";
		last;
	}
}

#send a HELO if we succesfully connected
if ($hello) {
	#reset timeout
	my $endtime = time + $timeout;
	
	# return timeout if we timeout waiting to write
	$ipHash{'Message'} .= '<br>Connection timed before HELO' unless $sel->can_write( $timeout ); # timeout
	
	# send the hello message
	$socket->syswrite("HELO $hostname", length("HELO $hostname"));
		
	# read lines until we get a 250 or time out		
#				my $line;
	my $ableToSend;
	while ( time < $endtime && ! $@ ) {
		# read a line - should time out when the endtime is here
#					unless ($sel->can_read( $endtime-time )) {
			# returns time out
#						$ipHash{'Message'} .= '<br>HELO response timed out';
#						last;
#					}

		my $bytes = $socket->sysread( $line, 4096, length($line) );

			# check the output
		if ($line =~ /^250/m) {
			# finish the connection, waiting up to 10 seconds
			$socket->syswrite("QUIT\n", length("QUIT\n")) if $sel->can_write( 10 );
				
			# return ok
			$ipHash{'Message'} .= "<br>Replied to HELO";
			$ableToSend = 1;
			last;
		}
		else {
			$ipHash{'Message'} .= "<br>HELO error: $line";
			last;
		}
	}
	
	# if we didn't connect
	unless($ableToSend) {
		$ipHash{'Message'} .= "<br>Did not reply to HELO";
	}
}
else {
	$ipHash{'Message'} .= "<br>Could not establish connection or response timed out";
}
$socket->close();

#!/usr/bin/perl
use strict;
use warnings;
use IO::Socket::INET;

my($peeraddr) = "mydomain.com";

my($answer);
my($socket) = IO::Socket::INET->new(
    PeerAddr => "mail.$peeraddr",
    PeerPort => 25,
    Proto    => "tcp",
    Type     => SOCK_STREAM
) or die "$0: Socket connect failed: $!\n";

$answer = <$socket>;
if($answer !~ /^220/) {
  print "open failed: got '$answer'\n";
  close $socket;
  exit;
}

print $socket "HELO $peeraddr\n";
$answer = <$socket>;
if($answer !~ /^250/) {
  print "HELO failed: got '$answer'\n";
  close $socket;
  exit;
}
#... rest of script clipped