[isalist] SMTP Connection Closed - Solved
- From: "ISA" <ISA@xxxxxxxxxxxxxxxx>
- To: <isalist@xxxxxxxxxxxxx>
- Date: Tue, 6 Feb 2007 10:23:39 -0500
Everyone - I just wanted to thank everyone for all your help. It appears
as the problem was solved, but the solution is still a bit mysterious.
To recap the problem:
1) I have a new client that I setup a new network for including the
domain, T1 line, SBS 2003 RS etc. After I was done I tested the mail
which worked fine inbound/outbound EXCEPT when sending to MY server.
2) My server is an Exchange 2003 (fully patched) running GFI
MailEssentials and behind an ISA 2004 (fully patched). During my
troubleshooting I SHUT OFF MailEssentials and all Exchange filtering -
still no good.
I checked the ISA real time logs and watched as the SMTP connection was
created, the broken down (within 5 seconds).
Long story short, I submitted a Reverse DNS zone entry to my client's
ISP on Friday - and by Sunday mail was coming in with lightning speed.
QUESTION: what was blocking the mail from coming in? ISP?
________________________________
From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx]
On Behalf Of Jim Harrison
Posted At: Friday, January 19, 2007 11:44 AM
Posted To: ISA
Conversation: [isalist] Re: SMTP Connection Closed
Subject: [isalist] Re: SMTP Connection Closed
Captures
Isa live logging
Get it
Quit guessing
From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx]
On Behalf Of Gerald G. Young
Sent: Friday, January 19, 2007 6:51 AM
To: isalist@xxxxxxxxxxxxx
Subject: [isalist] Re: SMTP Connection Closed
Resending since the first message got garbled.
> I enter telnet mail.domain.com 25 (hit enter) the line disappears and
> the curser just sits there and blinks - no banner - nothing. If I hit
> enter again it goes back to the C:\ prompt.
This is a half pipe opening but not being able to complete the
connection, as your ISA logs also seem to be indicating. Is this
occurring only from one location? What happens if you telnet to the ISA
box from a source on the same subnet as it is? Do you still see these
half pipes?
Several other people reported being able to connect to your system
without problems, so continue to validate the scope of the issue. Is it
just a single remote location that is having the problem or are there
many?
I was also able to successfully connect.
In the past one cause of this behavior was a asymmetric route; a member
of a firewall (CheckPoint) pair died without dying (accepted traffic but
didn't process any) and because of that, traffic would come in through
one member and attempt to go back out through the other.
If this is only occurring from one location, you may want to see what
kind of network devices they have sitting between the client you are
telnetting from and the server to which you are telnetting.
HTH.
Cordially yours,
Jerry G. Young II
Product Engineer - Senior
Platform Engineering, Enterprise Hosting
NTT America, an NTT Communications Company
22451 Shaw Rd.
Sterling, VA 20166
Office: 571-434-1319
Fax: 703-333-6749
Email: g.young@xxxxxxxx
All mail to and from this domain is GFI-scanned.
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