error 527 outllook

Posted on 2008-06-25
Last Modified: 2013-11-30
Everytime we want to send an email to this address from the FLExch server the emails do not go through, we recieved the below unreachable error message 527. We do not have problem with NYEXCH server when sending email to this domain. The email goes well, and client is able to reply. I check with our service provider and the rdns record is fine @ the space.
our emails are format this way in florida   
our emails are format this way in new york

Please help me wiht this. I really appreciate it. Below is the error we get in the Florida office:
Sent: Tuesday, June 24, 2008 5:01 PM
To: Daniela Solivan
Subject: Returned mail: unreachable recipients:<email removed>
The original message was received at Tue Jun 24 17:01:23 2008

Likely reason for failure: 527 (
Question by:Faustinoeltino
  • 6
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Expert Comment

ID: 21865644
Is your Fl-Exch directly sending out? Have you double checked the ip address it is coming in with at the recipients server?

You could try to simulate a SMTP session with the telnet command from the exchange server. There you can more exactly see the messages of the recipients server. Capture your telnet session and post the output here... (e.g. with Hyperterminal)

Some more details on testing smtp connections can be found here:

Author Comment

ID: 21957539
this is what i found when i enter our ip (i just changed a few number) on  However, our format is could it be a problem if we have name on the space but, i do not think so because it is only with this domain . Please let me know what you think and thanks for your help. bu query was :
Reverse DNS lookup for is

Warning: Supplied argument is not a valid MySQL result resource in /var/www/html/lookup/index.php3 on line 151 IS NOT directly held within the database
We directly import and use, several external sources of well maintained data.
Your IP address may be listed on one or more of those lists.
If you have poor security, or have been greatly abused, you will probably be on many lists.
You must follow their processes and procedures to get removed from each of those external lists.
You must determine which list/s you're on, and ask the source database to remove your entry.
The is an aggregated summary of all the lists detailed below.
All the lists have their own specific pages detailing a great deal of information.
Please DO NOT CONTACT US about removal processes.

Expert Comment

ID: 21971660
Sorry for the delay, what do you exactly mean with "we have name on the space"?

Have you tried to access the recipients server with telnet for further testing?
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Author Comment

ID: 21972774
I tried but things did not work when i use those commands. Is this should be done from the exchange box?
I send an email to the IT guys @ kiwitours. and I explained them that this is only a problem when i have the Florida office sending out emails to them. This is what they reply to me. Below is our orginal IP. Just be careful. He is talking about creating an A records, so this must be done in DNS correct? Please help me if this is correct. Thanks.
Dear Fausto,
I have contacted our Internet Provider and he sent me following message.
It's in german but I hope you have somebody who can translate it.
I think the important message is this:
Make changes in your mailsystem:
Change the name to "" and the IP in
A-Records in
Sorry my english is not so good, but i hope you understand it.

Expert Comment

ID: 21973718
Correct, you should test on / from the Exchange box itself.

OK, I'm a little confused of what you said...., however I try to compile the information I read in my mind. In the meanwhile I will check some things on DNS lookup:

a.) Trying to resolve the PTR-record of the ip-address gives me the host name ''
b.) Trying to resolve the A-record of the host name '' gives me the ip-address of 65.218.x.x

And here we go!!! Reverse-lookup must be the same as the forward-lookup. Which is not the fact for your ''. Many more recipient-systems are checking this due to the increasing amount of spam. I assume is blocking anything that has a incorrect DNS check.

So you should confirm that the A and PTR record for the host '' is correct.

c.) Trying to resolve the PTR-record of the ip-address 65.218.x.x gives my the host name ''

The question now is (as it was before): which ip-address is used by '' when talking to the internet? This one must be consistent in the DNS records. Otherwise no chance...

Expert Comment

ID: 21973771
OK, I also tried to see how your NY office looks like:

d.) Trying to resolve the MX-record of the domain '' gives me the host name ''
e.) Trying to resolve the A-record of the host name '' gives me the ip-address of 65.220.x.x
f.) Trying to resolve the PTR-record of the ip-address 65.220.x.x gives me the host name ''

Author Comment

ID: 21973817
This is what my service prodiver told me.

Reverse DNS for this IP is set up as follows:
If this needs to change, let us know.

So to change the A and PRT records must be done in DNS Server correct?

Expert Comment

ID: 21973867
Yes, you're right. It's a DNS issue that has to be change on the DNS servers of your provider. You have to ask your provider to set the records according to the real address you are using. (I assume you're using uunet)

So, if your host '' uses the internet address of, both A and PTR record have to point to this ip-address and name! Which means that your current PTR record for '' is wrong!

Accepted Solution

karwak earned 125 total points
ID: 21973880
Sorry, too busy today ;-)...

I meant your A record for '' is wrong! It resolves to the wrong ip-address!

Sorry again...

Author Closing Comment

ID: 31470553
DNS issue.

Author Comment

ID: 21982010
A record need to be change. I contact our service provider for this change. Excellent answer. Thanks a lot,

Expert Comment

ID: 22291763
I have just spent several minutes removing sensitive information from the question.

karwak, do not ever post sensitive information that you do not wish revealed to Experts Exchange.  It's a lot more work for us to fix it, than it is for you to hold it back.

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