SMTP mail and "unreachable" node

[Bill Pedersen]

Ok, given my investigation of rDNS then using nslookup and PTR records I get:

$ multi nslookup charon.stromasys.com/type=ptr
Server: LOCALHOST
Address: 127.0.0.1

Authoritative answers can be found from:
STROMASYS.COM
origin = ns1.register.eu
mail addr = info.register.eu
serial = 2009102202
refresh = 7200 (2H)
retry = 3600 (1H)
expire = 86400 (1D)
minimum ttl = 3600 (1H)
$ multi nslookup ccsscorp.com/type=ptr
Server: LOCALHOST
Address: 127.0.0.1

Authoritative answers can be found from:
CCSSCORP.COM
origin = ns1.got.net
mail addr = dns-admin.got.net
serial = 2009030601
refresh = 10800 (3H)
retry = 3600 (1H)
expire = 604800 (1W)
minimum ttl = 86400 (1D)
$ multi nslookup charon.stromasys.com info.register.eu
*** Can't find server address for 'INFO.REGISTER.EU':
Unknown host
Server: LOCALHOST
Address: 127.0.0.1

Non-authoritative answer:
Name: CHARON.STROMASYS.COM
Address: 213.173.170.13

So to my untrained eye this looks "ok".

So, now the question is "What is ingres.com seeing when the SMTP connection is established?" Or at least that is what I would suspect might be the consideration.

Bill.

[Bill Pedersen]

I was so quick since it gave the number I was expecting I missed the error message that it could not find info.register.eu...

So I guess my untrained eye is still lost.

Insight please.

Thanks,

Bill.

[Jim_McKinney]

> So, now the question is "What is ingres.com seeing when the SMTP connection is established?"

ingres.com shouldn't be receiving a direct connection from your system. Any mail that you send to them should go to one of the hosts defined by the DNS MX records associated with ingres.com (69.18.136.194 -proofpoint1.invision.net or 69.18.136.195 - proofpoint2.invision.net). Your system would send mail to one of them and then they would later relay it on to the system with the addressee's mailbox (perhaps after performing some virus checking or what-have-you). You might try simulating an SMTP session to one or both of these hosts using telnet on port 25 and see what happens. The recipe for that is similar to what follows (your telnet command line might differ slightly - the following presumes MultiNet's telnet CLD)

$ TELNET/PORT=25 proofpoint1.invision.net
helo
mail from:
rcpt to:
data
put all of your
message text here
.
quit

[Bill Pedersen]

ok, yes, I understand that proofpoint... is doing the email processing for ingres.com. The issue being as far as I can concerned it is ingres.com - in the long run. The same as a normal email recipient at ingres.com would think.

Yes, ok so when I find the time I will test the telnet operation to see what is happening there.

[Hoff]

SMTP traffic from an SMTP server with invalid rDNS will not be accepted by most modern mail servers.

[Jim_McKinney]

> SMTP traffic from an SMTP server with invalid rDNS will not be accepted by most modern mail servers.

Yes, this is true for many servers - and if they terminate your connection for this reason they usually say so during the SMTP dialogue - simulate an SMTP conversation or use TCPDUMP to watch one and you'll likely learn if this is the case here. This case is certainly distinct from the "unreachable node" scenario that began this thread.

[Bill Pedersen]

Using TCPDUMP I end up with an interesting message:

0x0000: 4500 0063 c89f 4000 3006 3465 4512 88c3 E..c..@.0.4eE...
0x0010: d5ad aa0d 0019 c05b ec26 6be1 4661 421e .......[.&k.FaB.
0x0020: 5018 05b4 a38a 0000 3535 3420 7072 6f6f P.......554.proo
0x0030: 6670 6f69 6e74 322e 696e 7669 7369 6f6e fpoint2.invision
0x0040: 2e6e 6574 2045 534d 5450 206e 6f74 2061 .net.ESMTP.not.a
0x0050: 6363 cc


ESMTP not accepting...

I can not believe that HP SMTP would not talk to an Extended SMTP but...

In using telent to port 25...

$ telnet proofpoint1.invision.net 25
%TELNET-I-TRYING, Trying ... 69.18.136.194
%TELNET-I-SESSION, Session 01, host proofpoint1.invision.net, port 25
554 proofpoint1.invision.net ESMTP not accepting messages
HELO charon.stromasys.com
250 proofpoint1.invision.net Hello [213.173.170.13], pleased to meet you

There is a fair pause between when the "...port 25" is printed and then the "554 ..." error message.

It would appear that OpenVMS SMTP does not support, ie does not email, the necessary information to be recognized by the remote system.

And in getting the 554 message then goes and places the message back in the queue when in fact it should continue.

Thoughts?

Thanks,

Bill.

[Bill Pedersen]

Here is a sample between two different servers:

$ telnet mx2001.mx2.got.net 25
%TELNET-I-TRYING, Trying ... 209.66.101.139
%TELNET-I-SESSION, Session 01, host mx2001.mx2.got.net, port 25
HELO stromasys.comEscape character is ^]
220 mx2001.mx2.got.net ESMTP Wed, 23 Dec 2009 13:13:38 -0800
250 mx2001.mx2.got.net Hello [213.173.170.13], pleased to meet you
TELNET> exit
%TELNET-S-LCLCLOSED, Local connection closed
-TELNET-I-SESSION, Session 01, host mx2001.mx2.got.net, port 25
$ telnet proofpoint1.invision.net 25
%TELNET-I-TRYING, Trying ... 69.18.136.194
%TELNET-I-SESSION, Session 01, host proofpoint1.invision.net, port 25
HELO stromasys.comEscape character is ^]
554 proofpoint1.invision.net ESMTP not accepting messages
250 proofpoint1.invision.net Hello [213.173.170.13], pleased to meet you

Mail through got.net eventually ends up at ccsscorp.com.

In using telnet from my laptop to proofpoint1.invision.net I get a similar 554 message...

If I then go ahead and try to send a message it accepts the HELO but then rejects any following messages.

I suspect that there is more that needs to be passed between the two systems so as to be happy with the connection before proceeding. The what is the big issue now.

Bill.

[Hoff]

>Yes, this is true for many servers ...

Yes, true, and it's likely also true that if the DNS isn't corrected, then the whole process of resolving the connectivity will be for naught. (OpenVMS with TCP/IP Services is one of the few boxes that doesn't look at this stuff.)

> I can not believe that HP SMTP would not talk to an Extended SMTP but...

Google: "Your search - site:h71000.www7.hp.com esmtp - did not match any documents."

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1101097

[Bill Pedersen]

Ok, Hoff, so what needs to be changed in the DNS. As far as I can tell it is ok at least from my prospective of looking at the records.

If can can provide a pointer as to what needs to be changed I would be happy to make sure the changes are implemented.

Thanks,

Bill.