asked on

Some emails are returned

How can I troubleshoot some issues with my exchange server when some emails are returned at random. It does not happen on a daily basis but important emails to some users are been returned. The email address is correct.

Today's email error is as follow:

This is an automatically generated Delivery Status Notification.

Unable to deliver message to the following recipients, due to being unable to connect successfully to the destination mail server.

emailaddress@server.net (removed on purpose)

Reporting-MTA: dns;servername.net (actual server name changed) Final-Recipient: rfc822;emailaddress@server.net Action: failed Status: 4.4.7 X-Display-Name: emailaddress@server.net

Any help is greatly appreciated.

jffrybauer

Hi rauladan:

These are for emails being sent from your company to outside email addresses and you receive the NDR's back?

If so, is your reverse DNS set up correctly for your mail server IP? You server IP should resolve to your mail server A record when doing a reverse lookup.

Check your IP here:

http://remote.12dt.com/

rauladan

ASKER

It points to our ISP (bellsouth.net). It does not show the domain name.

I will work on that and let you know the results. Thank youuuuu.

jffrybauer

you should be able to submit a request to your ISP for them to modify your PTR (since they maintain the reverse zone for your public IP range).

should read:

PTR 1.2.3.4 host.domain.com

where 1.2.3.4 is your public IP and host.domain.com is your mail server hostname.

rauladan

ASKER

The reverse DNS resolve correctly now to the proper domain name but the problem is still there. Do you have any suggestions on how to troubleshoot this issue?

Here is a copy of the message:

Your message did not reach some or all of the intended recipients.
Subject: Documents
Sent: 8/18/2010 8:48 AM
The following recipient(s) cannot be reached:
username@comcast.net on 8/18/2010 9:51 AM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
<domainname.net #4.4.7>

jffrybauer

Since the record was pointing to your ISP instead of your server, you may have been added to one or more blacklists. Try searching here:

http://mxtoolbox.com/blacklists.aspx

to see if you're server is listed. If so, you will have to submit requests to remove now that the issue is resolved.

ASKER CERTIFIED SOLUTION

jffrybauer

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

rauladan

ASKER

Was wondering why I never got a response. Just signed on and saw your response. I appreciate it very much. Anyway, no they are not blacklisted. I had checked on that before.

Thank you. I am adding the SPF record and will let you know the outcome.

Thank you again.

jffrybauer

You can try more lookups here:

http://www.dnsbl.info/dnsbl-database-check.php

and here:

http://www.dnswatch.info/dns/rbl-lookup?host=66.212.2.102&submit=RBL+Lookup

Also, depending on how long your ISP has their DNS zone time to live set for, it could take 24 - 48 hours from the time they made the change to propagate across the internet.

Have you done another reverse lookup to make sure they entered the reverse record correctly?