"Unable to bind to the destination server in DNS."

[theomen]

Ok, I'm having all sorts of problems with my Exchange server today, it's onow 9.20pm and I'm still working on this thing.

I have a huge queue of emails waiting to send (118 domains listed, each with several emails).

There are 2 things happening, depending on settings:

1) The emails sit on "Active" for ages, but don't do anything.

2) The emails go from ready to active, then to retry. There are 2 different errors which come up depending on settings:
i) "Unable to bind to the destination server in DNS. "
ii) "The remote server failed to respond to a connection attempt".

I've not changed anything with the exchange server recently and so can't understand why its suddenly gone mad like this.

Any ideas? I've currently got our ISP's smtp server setup as the smart host, and the IP address of that host in the "external dns".

 

[Zelandakh]

TAKE A FULL BACKUP!

Check event viewer and telnet as previously detailed.

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[theomen]

Taking daily backups now anyway, when I took over the role the email had never been backed up, and neither had our development server containing all client solutions.

I've just taken another to make sure.

Gonna try the telnet now.

 

[theomen]

I am able to telnet into the server both internally and externally.

I've emailed our web hosts requesting a copy of our zone file, see what ip it is pointing to and see if I can find anything out from there.

 

[theomen]

Doesn't work with port 25 though

 

[Zelandakh]

not even internally? if not internally then the SMTP virtual server is stopped


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[theomen]

From our online web server, I telnet to our external IP which takes us into our ISA server. I can login to the server if I do not specify a port number, but it can't connect if I specify port 25.

Internally, I try telnetting into the local IP for the mail server using port 25, which then comes up with the following and stops there:

"220 mail.[domain] Microsoft ESMTP MAIL service, Version 5.0.2195.6713 ready at sun, 24 oct 2004 22:06:32 +0100"

Our ISA server is supposed to forward any requests to port 25 to the mail server as far as I can see, though I've not been given any training on these servers since taking on the additional techie support responsibilites so I'm not too sure.

 

[Zelandakh]

ok, your Exchange is fine. This is either an ISA or an ISP / MX record issue. My bet is ISA - 90%.

Your Exchange work is done if you've done the backup. Who last played with the ISA? If it was you, let's crack this baby either here or in the ISA forum. Otherwise, take 2 whiskies and blame someone in the morning.

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[theomen]

I'm supposed to be the only one who touches the server, so it probably is me thats broken it. Probably sometime between Friday morning and 12.45am Saturday morning when I was trying to get outgoing mail working.

Main problem is I can't remember all the changes I've made, so I've been going through the ISA server tonight just checking all settings, but not knowing a lot about it doesn't help.

Would like to get it working tonight if possible so I can try and get tomorrow off in return for all the work over the weekend.

Thanks for your help so far by the way

 

[Zelandakh]

well, the yanks are online now but it is Sunday night for them so it will be slow.

Recommend you get a good night kip and get in early tomorrow. Your internal Exchange is ok. Can you send out now or not?

Hopefully your MX record is set to back off elsewhere while Exchange is offline. You have a bit of grace.

I've got a problem called full time employment but I'll try to check this thread. Reply to update please?

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[theomen]

I can send out no problem now, and can send and receive internal emails, its just receiving external thats the problem.

I'm just going to check another couple of bits then I'm getting some sleep myself, been up late for the last 3 nights.

Thanks again, will update you tomorrow.

 

[Zelandakh]

by the way, I picked up this thread around 9.30pm on Friday (local time). If it was 10 minutes old, that puts you in the UK. If so, check out Tek Tips UK forum.

If not, please ignore me as I'm drumming up business!

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[theomen]

Yeah, I am in the UK, but didn't know about the UK forum Will check it out.

 

[theomen]

I got the zone file back this morning from our web hosts.

The MX record is as follows:

[domain].[tld] MX 10 mail.[domain].[tld]

Mail in A [external ip]

I have tried connecting to the ip through telnet. If I don't specify a port, it can't connect. If I do specify port 25, it comes up "Press any key to continue..." and stops there, pressing keys doesn't do anything the first time, but if I hit a key again it comes up with "connection lost".

 

[theomen]

I've done a tracert on our IP as well.

It goes through fine until it seems it gets to our router.

It resolved to "[our username].plus.com [our router ip]" (rather than the external ip we use to connect from outside, and to which the mx record points to), but subsequent requests time out.

To me it seems that out router is blocking access rather than the ISA server?

 

[theomen]

All is now working

Turned out to be a strange IP address that had been set up in the exchange server, which was quite similar to our external IP, but not the same.

All is well now though

Thanks for the help.

 

[Zelandakh]

Pleased you got it sorted.

Join TTUK and at the next meet you can buy me a pint.

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[theomen]

I would if I could find it

Tried tek-tips.co.uk, and tried searching google. What is the url?

 

[Zelandakh]

top of this page is find a forum. type in:

tek-tips in the uk

And you'll find the member moderated forum.

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[theomen]

Found it, just applied for membership.

Same problem again you see, always looking in the wrong places