Hi all,
do you remember my mails last two weeks regarding a problem "MX connect fail"?
Thanks to all for the help and info I got. I have now found the reason why it came to
this situation and wanted to share this info with you.
Mail machine is a WinNT box with two NICs, one for internet (over a router from ISP),
the other is connected to intranet. When we installed IMail the first time the
connection to the internet was not available yet. But our customer wanted to test it
so far on the intranet. Because this mail server has to serve four different domains
we set up IP with four addresses on the intranet and one address (at this time we used
one of the public ip-addresses) for internet.
When it came to the point hat the internet connection was ready we changed the
ip-address and on the first place everthing seemed to be fine. We then realized that
no mail was leaving this server. We checked IMail settings and did not find what was
going on. At this time I sent the first mail to this list regarding this issue. All
answers pointed me to the direction that there is something wrong with our/ISPs DNS
configuration. Yes, there was a mistake in DNS settings of the ISP, but it did not
affect our problem. I checked "debug messages" in SMTP, checked the logs and found
that Imail tried to send mails out to the internet with a sender�s ip-address of one
of the intranet addresses. I removed all NICs and ip-addresses and reinstalled all
(NICs, protocols, addreses, SP5) to get a clear system again. Now Imail showed up with
the correct addresses regarding to the logs but still could not send a single message!
You can imagine that I tested every single possibility I found in KB regarding �MX
connect fail� (entered addresses in hosts file, checked DNS with WS_PingPro and
nslookup, telnetted to port 25 on our own mail server and created a message, and so
on). Still no go.
Yesterday, while searching the KB (I was nearly giving up on this prob), I found a
info describing a more verbose config of smtp service. And now the logs showed me that
again the server tried to deliver mails to other domains presenting them one of the
internal ip-addresses. After going directly to registry and changing all domains to
the internet ip-address I wanted to use...all pending mails were deliverd in a rush.
IMHO, what it really made difficult to me to find the config mistake was that although
I checked logging for SMTP, the messages generated were not as useful as they could
have been to show that smtp service used the wrong ip-address while trying to deliver
a mail. It did show which ip-addresses were used for domains, that smtp started on
port 25, that DNS lookups worked, but it did not show up with a hint that it used a
internal ip-address while delivering a mail to another internet MX.
Nevertheless it was my mistake not a mistake of the software! We will now continue
testing and add users to the system as well as entering port filters to secure machine
form outside world...
I hope that everything works fine now :-))
Again thanks for all the help I found on this list. I hope I can give back some of
what I learned now.
Ruediger Sobeck
[EMAIL PROTECTED]
Please visit http://www.ipswitch.com/support/mailing-lists.html
to be removed from this list.
