RE: Multiple MX Records
- From: "John Tolmachoff \(Lists\)" <johnlist@xxxxxxxxxxxxxxxxxxx>
- To: "'[ExchangeList]'" <exchangelist@xxxxxxxxxxxxx>
- Date: Thu, 18 Dec 2003 10:01:06 -0800
More coffee? I am still trying to get my first cup. ;)
John Tolmachoff
Engineer/Consultant/Owner
eServices For You
-----Original Message-----
From: Mulnick, Al [mailto:Al.Mulnick@xxxxxxxxxx]
Sent: Thursday, December 18, 2003 9:37 AM
To: [ExchangeList]
Subject: [exchangelist] RE: Multiple MX Records
http://www.MSExchange.org/
Good point John. Rereading it, I was assuming that the problem was that the
server wasn't trying the secondary. I didn't look closely enough at the
error.
Thanks for straightening that out. <pads off to drink more coffee>
_____
From: John Tolmachoff (Lists) [mailto:johnlist@xxxxxxxxxxxxxxxxxxx]
Sent: Thursday, December 18, 2003 11:38 AM
To: [ExchangeList]
Subject: [exchangelist] RE: Multiple MX Records
http://www.MSExchange.org/
The problem is all on the receiving end. By starting a session and returning
a 421 code, they are telling your server to try again later. Your server is
doing exactly what it was told to do. There is no reason for your server to
try the other MX records. BTW, the following information is available at
http://www.networksorcery.com/enp/rfc/rfc1893.txt
4.X.X Persistent Transient Failure
A persistent transient failure is one in which the message as
sent is valid, but some temporary event prevents the successful
sending of the message. Sending in the future may be successful.
X.2.X Mailbox Status
Mailbox status indicates that something having to do with the
mailbox has cause this DSN. Mailbox issues are assumed to be
under the general control of the recipient.
X.2.1 Mailbox disabled, not accepting messages
The mailbox exists, but is not accepting messages. This may
be a permanent error if the mailbox will never be re-enabled
or a transient error if the mailbox is only temporarily
disabled.
John Tolmachoff
Engineer/Consultant/Owner
eServices For You
-----Original Message-----
From: paul_lemonidis@xxxxxxxxxxx [mailto:paul_lemonidis@xxxxxxxxxxx]
Sent: Thursday, December 18, 2003 5:31 AM
To: [ExchangeList]
Subject: [exchangelist] Multiple MX Records
http://www.MSExchange.org/
Hi All
Has anyone else come across this one? I have outbound messages queued up for
domains where there primary server is down. These queue up and are not
delivered which would seem fair enough on the face of it. Just one problem
the destination system has multiple MX records and the other hosts are up.
Why does Exchange refuse to use them? Even if I force the connection they do
not leave? Eventually they go of their own accord but this takes several
minutes or even hours? I cannot say at this stage if this is as a result of
the primary server coming back on line. I suspect it is.
> server 217.20.32.36
Default Server: ns1.lon.ipmh.telecity.net
Address: 217.20.32.36
> set q=mx
> mtsn.org.uk
Server: ns1.lon.ipmh.telecity.net
Address: 217.20.32.36
Non-authoritative answer:
mtsn.org.uk MX preference = 10, mail exchanger =
scanmailext.easymail.va.ifl
.net
mtsn.org.uk MX preference = 20, mail exchanger = mx1.easymail.va.ifl.net
mtsn.org.uk MX preference = 30, mail exchanger = mx2.easymail.va.ifl.net
mtsn.org.uk nameserver = dns2.rmplc.co.uk
mtsn.org.uk nameserver = dns0.rmplc.co.uk
mtsn.org.uk nameserver = dns1.rmplc.co.uk
scanmailext.easymail.va.ifl.net internet address = 213.18.255.195
mx1.easymail.va.ifl.net internet address = 213.18.248.112
mx2.easymail.va.ifl.net internet address = 213.18.248.112
>
I can telnet the second server just fine. The first one drops the connection
almost immediately. I suspect that is the answer? I am guessing that since
it does make a connection of sorts, albeit very briefly, it never tries the
second record as it thinks it is connected and thus never checks the other
MX records.
Above and below are relevant screen shots.
421 SMTP service not available, closing transmission channel
Connection to host lost.
Can someone tell me if I am correct and if there is any way around this
please. I know that strictly speaking, if my theory is correct, it could be
classed as a firewall issue at the remote end but that doesn't help me
deliver mail. The only short term way I see around this is to set up an
extra Virtual SMTP server and restrict the address space to just that domain
and forward to the second record host explicitly rather than using DNS.
Although that won't help with the trapped messages I suspect?
Any ideas, comments or suggestions please?
Many thanks in advance,
Regards,
Paul Lemonidis.
------------------------------------------------------
List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist
Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp
Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ
------------------------------------------------------
Other Internet Software Marketing Sites:
Leading Network Software Directory: http://www.serverfiles.com
No.1 ISA Server Resource Site: http://www.isaserver.org
Windows Security Resource Site: http://www.windowsecurity.com/
Network Security Library: http://www.secinf.net/
Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com
------------------------------------------------------
------------------------------------------------------
List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist
Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp
Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ
------------------------------------------------------
Other Internet Software Marketing Sites:
Leading Network Software Directory: http://www.serverfiles.com
No.1 ISA Server Resource Site: http://www.isaserver.org
Windows Security Resource Site: http://www.windowsecurity.com/
Network Security Library: http://www.secinf.net/
Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com
------------------------------------------------------
------------------------------------------------------
List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist
Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp
Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ
------------------------------------------------------
Other Internet Software Marketing Sites:
Leading Network Software Directory: http://www.serverfiles.com
No.1 ISA Server Resource Site: http://www.isaserver.org
Windows Security Resource Site: http://www.windowsecurity.com/
Network Security Library: http://www.secinf.net/
Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com
------------------------------------------------------
Other related posts:
