Intermittent SMTP timeout issue.

Intermittent SMTP timeout issue.

Post by mabbe » Sun, 02 Nov 2003 10:49:22


Greetings,

This Exchange server times out when trying to communicate with some
other SMTP servers on the Internet.

This is typical of a SMTP conversation that ends in a time out. This
is from the SMTP log with the actual domains in use removed from the
user fields.

-----

2003-11-01 00:59:32 205.228.12.103 OutboundConnectionResponse SMTPSVC2
OHPDC2 - 25 - - 220+hqvsbh1.ms.com+ESMTP+external+Postfix.+NO+UCE 0 0
49 0 31 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionCommand SMTPSVC2
OHPDC2 - 25 EHLO - smtp.mydomain.com 0 0 4 0 31 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionResponse SMTPSVC2
OHPDC2 - 25 - - 250-hqvsbh1.ms.com 0 0 18 0 31 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionCommand SMTPSVC2
OHPDC2 - 25 MAIL - FROM:< XXXX@XXXXX.COM >+SIZE=6744 0 0 4 0 31 SMTP -
- - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionResponse SMTPSVC2
OHPDC2 - 25 - - 250+Ok 0 0 6 0 47 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionCommand SMTPSVC2
OHPDC2 - 25 RCPT - TO:< XXXX@XXXXX.COM > 0 0 4 0 47 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionResponse SMTPSVC2
OHPDC2 - 25 - - 250+Ok 0 0 6 0 62 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionCommand SMTPSVC2
OHPDC2 - 25 DATA - - 0 0 4 0 62 SMTP - - - -
2003-11-01 00:59:32 205.228.12.103 OutboundConnectionResponse SMTPSVC2
OHPDC2 - 25 - - 354+End+data+with+<CR><LF>.<CR><LF> 0 0 35 0 78 SMTP -
- - -

----

Once the "354 End+data+with" field is given the SMTP conversation
times out.

The message will usually sit in the queue and retry until the (2) day
default time out period, then a NDR gets kicked back to the sender.

Has anyone seen anything like this before? I've tried just about
everything rational except reinstall Exchange.

Server: Windows 2000 SP4 + Exchange 2000 w/ SP3 + roll up pack +
hotfixes.

Exchange: One server, one site. Standard Edition.

Thanks.

-Mike
 
 
 

Intermittent SMTP timeout issue.

Post by Denis McDo » Wed, 05 Nov 2003 00:35:06

If the issue is only to certain domains, there are a couple of things to
look at:

1. Check your firewall settings. Certain SMTP proxies or other features
running on port 25 can interfere with communications. Since different
servers advertise different SMTP\ESMTP verbs, and the firewalls don't always
support all of the verbs, this would help explain the sporadic nature of the
problem. Disable any proxies running on port 25 of your firewall to see if
the issue is impacted.

2. Take a Network Monitor capture to look at the SMTP transaction between
the servers.

--
--
Denis McDowell [MSFT]

This posting is provided "AS IS" with no warranties, and confers no rights.

 
 
 

Intermittent SMTP timeout issue.

Post by mabbe » Wed, 05 Nov 2003 21:57:24

i Denis,

I thought the firewall might be an issue as well. The server that
this is running on (Dell PE 2650) has (2) NICs, so I configured the
second NIC (which is usually disabled) with the server's WAN IP
address and connected it directly to the Internet router. I still had
the same problem.

Besides the network capture, it seems to me that my next logical step
would be to reinstall IIS and Exchange. What do you think about doing
this as per KBASE article 320202 to address this SMTP problem? Is
there a more detailed way of reinstalling only the SMTP module of IIS
that doesn't require a complete reinstall of IIS and Exchange?

Thanks,

Mike



"Denis McDowell, MCSE [MSFT]" < XXXX@XXXXX.COM > wrote in message news:< XXXX@XXXXX.COM >...
 
 
 

Intermittent SMTP timeout issue.

Post by Danny Luon » Wed, 05 Nov 2003 23:53:34

i Dennis

Part 1
On Exchange server, telnet locahost 25 or telnet [local IP]
After the banner comes up, then type "ehlo mike.com"
copy the listing and paste to your reply message

Part 2
Now, on a public network (Internet)
Telnet [your netowkr public IP] 25
Ehlo mike.com
copy and paste the listing to your reply message


Part 1 will tell us whether you have all your Exchange eSMTP verbs, if some
are missing, then an IIS remove/reinstall is not necessary and you can
simply use a tool called SMTPreinstall found on the Exchange CD support
tools to re-associate the IIS SMTP components with Exchange

If Part 1 does show the esmtp verbs and Part 2 doesn't, then a device on the
network node is preventing the verbs from passing though to or from the
Internet

Let me know the results before proceeding to drastic measures such as
uninstalling anything.


--
Regards,
Danny Luong

Exchange Enterprise Messaging Connector Engineer
XXXX@XXXXX.COM
Please do not send email directly to this alias. This is for newsgroup
purpose only.

This posting is provided "AS IS" with no warranties, and confers no rights."
--------------------------------
"M.A." < XXXX@XXXXX.COM > wrote in message
news: XXXX@XXXXX.COM ...
message news:< XXXX@XXXXX.COM >...
always
the
if
between
rights.


 
 
 

Intermittent SMTP timeout issue.

Post by mabbe » Thu, 06 Nov 2003 07:16:01

i Danny,

Here are the outputs from the Exchange server as requested:

Output Part 1:

220 smtp.mydomain.com Microsoft ESMTP MAIL Service, Version: 5.0.2195.6713 ready
at Tue, 4 Nov 2003 17:10:23 -0500
250-smtp.mydomain.com Hello [127.0.0.1]
250-TURN
250-ATRN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-X-EXPS GSSAPI NTLM LOGIN
250-X-EXPS=LOGIN
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-X-LINK2STATE
250-XEXCH50
250 OK


Output Part 2:

220 smtp.mydomain.com Microsoft ESMTP MAIL Service, Version: 5.0.2195.6713 ready
at Tue, 4 Nov 2003 17:02:53 -0500
250-smtp.mydomain.com Hello [12.41.24.10]
250-TURN
250-ATRN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-X-EXPS GSSAPI NTLM LOGIN
250-X-EXPS=LOGIN
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-X-LINK2STATE
250-XEXCH50
250 OK

It looks to me that all the esmtp verbs are intact both pre and post firewall.

Suggestions? Thanks for your input on this.

-Mike



"Danny Luong [MSFT]" < XXXX@XXXXX.COM > wrote in message news:< XXXX@XXXXX.COM >...
 
 
 

Intermittent SMTP timeout issue.

Post by Danny Luon » Fri, 07 Nov 2003 05:16:35

i Mike,

Go to dnsstuff.com, on the 3rd column, DNS lookup, key in your domain name,
select MX records and lookup
Sample info should be:




Domain Type Class TTL Answer
domainname.com MX IN 86400 mail.domainname.com [Preference = 10]
MX IN 86400
NS IN 86400
NS IN 86400
mail.domainname.com A IN 86400 IP address


Take your IP address as shown in your record and go back to the main page
and key the value in the field for Reverse DNS lookup.

Does the PTR record match the MX record?
Paste the result here if you need interpretation.

I believe the time-out might be occuring when the recipient mail server
performs a reverse DNS lookup on your mail server and it fails because
either PTR is missing or your PTR does not match the email msg header mail
server name.

--
Regards,
Danny Luong

Exchange Enterprise Messaging Connector Engineer
XXXX@XXXXX.COM
Please do not send email directly to this alias. This is for newsgroup
purpose only.

This posting is provided "AS IS" with no warranties, and confers no rights."
--------------------------------
"M.A." < XXXX@XXXXX.COM > wrote in message
news: XXXX@XXXXX.COM ...
ready
ready
firewall.
news:< XXXX@XXXXX.COM >...
some
the
rights."
things to
features
different
don't
nature of
see
some
This
the
SMTPSVC2
0 0
SMTPSVC2
SMTPSVC2
SMTPSVC2
SMTP -
SMTPSVC2
SMTPSVC2
SMTPSVC2
SMTPSVC2
SMTPSVC2
SMTP -
day
sender.


 
 
 

Intermittent SMTP timeout issue.

Post by mabbe » Sat, 08 Nov 2003 00:20:30

i Danny,

I think you're on to something here. While I did have a PTR record
for the IP address of the SMTP (Exchange) server, it was not
referencing the correct A record that is associated with the server.
The reverse lookup tool on dnsstuff.com was very helpful in pointing
this out.

I have made the change on my authoritative DNS servers. The TTL on
the zone file is set to 24 hours so I suppose I'll have to wait and
see if this resolves the intermittent SMTP timeout issue.

I'll post back tomorrow and let you know if it's resolved.

Thanks again for your assistance.

-Mike



"Danny Luong [MSFT]" < XXXX@XXXXX.COM > wrote in message news:< XXXX@XXXXX.COM >...
 
 
 

Intermittent SMTP timeout issue.

Post by mabbe » Sun, 09 Nov 2003 07:29:25

i Danny,

Correcting the hostname on the PTR record fixed the problem.

Thanks for your insight.

-MA


XXXX@XXXXX.COM (M.A.) wrote in message news:< XXXX@XXXXX.COM >...
 
 
 

Intermittent SMTP timeout issue.

Post by mabbe » Sun, 09 Nov 2003 07:29:26

i Danny,

Correcting the hostname on the PTR record fixed the problem.

Thanks for your insight.

-MA


XXXX@XXXXX.COM (M.A.) wrote in message news:< XXXX@XXXXX.COM >...
 
 
 

Intermittent SMTP timeout issue.

Post by Danny Luon » Tue, 11 Nov 2003 22:45:17

ou're welcome, M.A.

--
Regards,
Danny Luong

Exchange Enterprise Messaging Connector Engineer
XXXX@XXXXX.COM
Please do not send email directly to this alias. This is for newsgroup
purpose only.

This posting is provided "AS IS" with no warranties, and confers no rights."
--------------------------------
"M.A." < XXXX@XXXXX.COM > wrote in message
news: XXXX@XXXXX.COM ...
news:< XXXX@XXXXX.COM >...
news:< XXXX@XXXXX.COM >...
name,
page
server
mail
newsgroup
rights."
5.0.2195.6713
5.0.2195.6713
message
verbs, if
can
support
device on
from the
as
newsgroup
no
that
the
still had
step
doing
Is
of IIS
wrote in
firewalls
firewall to
transaction
confers no
with
out.
from
OutboundConnectionResponse
220+hqvsbh1.ms.com+ESMTP+external+Postfix.+NO+UCE
OutboundConnectionResponse
31
OutboundConnectionResponse
SMTP - - - -
OutboundConnectionResponse
OutboundConnectionResponse
78
conversation
the (2)
about
pack +