Re: Querying SSL/TLS capabilities of SMTP servers

8 Jul 2004

      It fails on hotmail.com; my script has problems there as well (and with 
couple others, the cure seems to be adding delays between the lines sent 
to the server; it makes the program slow, but more reliable).

In my case I added "-i 3" to the netcat options. Isn't a panacea, but 
helped in most cases. In the rest, I have to resort to telnet.

Thanks a lot. Seems I have to learn perl. Looks powerful.

On Thu, 8 Jul 2004, Justin wrote:
...
On 2004-07-08T17:50:57+0200, Thomas Shaddack wrote:
...
I cobbled up together a small bash shell script that does this. It lists 
the MX records for a domain, and then tries to connect to each of them, 
issue an EHLO command, disconnect, then list the output of the server, 
..
Or, in perl... though I wonder if there's a way to get capabilities with
Net::SMTP.  Might make this cleaner.
#!/usr/bin/perl
use IO::Socket;
use Net::DNS;
for ($i = 0; $i <= $#ARGV; $i++) {
    my @mx = mx($ARGV[$i]);
    foreach $record (@mx) {
  my $hastls = 0;
  my $mhost = IO::Socket::INET->new (
      Proto => "tcp",
      PeerAddr => $record->exchange,
      PeerPort => "25",
      Timeout => "10"
  );
  print $mhost "EHLO I-love-my-country.whitehouse.gov\n";
  print $mhost "QUIT\n";
  while (<$mhost>) {
      if (/STARTTLS/) {
      $hastls = 1;
      last;
      }
  }
  print "$ARGV[$i] " . $record->preference . " " . $record->exchange;
  print $hastls ? " adv-tls\n" : " no-tls\n";
  close $mhost;
    }
}