?
Solved

Exchange wont send email to particular domains

Posted on 2014-03-18
6
Medium Priority
?
585 Views
Last Modified: 2014-03-20
For the most part, our email works great.  However we are getting some failed emails to some (two) outside organizations.  The error in the Exchange Queue Viewer is Error: 450 4.7.1 Client host rejected: cannot find your hostname, [IPADDRESS].  The issue I see is the IP address it lists is the ip address we use to browse the internet, not the SMTP address.  There are reverse DNS and pointer records for both our primary and secondary MX records.
0
Comment
Question by:SidwellIT
6 Comments
 
LVL 8

Expert Comment

by:s3e3
ID: 39936926
It sounds like your firewall issue.
Are you sure your firewall is passing outbound SMTP traffic using the the IP address of the SMTP server ?

You can double check by sending yourself an email and looking at the headers.
0
 
LVL 19

Expert Comment

by:R--R
ID: 39937176
It should be the outside IP of the firewall.  Please try to telnet to the recipient mx from your network using telnet and check what output u get.
0
 

Author Comment

by:SidwellIT
ID: 39937209
When I view the header of an email I sent to my gmail, it is from the outside IP address of the firewall,

Received: from smtp-gateway.domain.edu ([OutsideIPofthFirewall])
        by mx.google.com with ESMTPS id 4si2386828qat.114.2014.03.05.19.36.39

I would have thought that it would use the public DNS entry for smtp-gateway.domain.edu instead of the IP address of the firewall.
0
Evaluating UTMs? Here's what you need to know!

Evaluating a UTM appliance and vendor can prove to be an overwhelming exercise.  How can you make sure that you're getting the security that your organization needs without breaking the bank? Check out our UTM Buyer's Guide for more information on what you should be looking for!

 
LVL 8

Assisted Solution

by:s3e3
s3e3 earned 1000 total points
ID: 39937225
no, the dns entry and firewall are interdependent.
you can either fix this from the firewall or adjust the dns servers and ensure the outbound ip has a reverse dns entry for sending mail. Maybe option 1 is easier depending on the firewall make and model .
0
 
LVL 63

Accepted Solution

by:
Simon Butler (Sembee) earned 1000 total points
ID: 39937301
Sounds like you haven't got your outbound NAT configured correctly on the firewall.
You need to check there so the traffic is going out the same way as it is coming in.

I would do that rather than trying to get the traffic accepted on your default IP address, that way you reduce the risk of getting blacklisted.

Simon.
0
 

Author Closing Comment

by:SidwellIT
ID: 39942161
Thanks guys!  Changing the Source IP for outgoing SMTP traffic solved our problem.
0

Featured Post

Simplify Active Directory Administration

Administration of Active Directory does not have to be hard.  Too often what should be a simple task is made more difficult than it needs to be.The solution?  Hyena from SystemTools Software.  With ease-of-use as well as powerful importing and bulk updating capabilities.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article describes Top 9 Exchange troubleshooting utilities that every Exchange Administrator should know. Most of the utilities are available free of cost. List of tools that I am going to explain in this article are:   Microsoft Remote Con…
This applies to Dell but may also apply to other manufacturers as well. We ran across a few machines that just dropped recently it trust relationship with the server. After doing the basic removing and joining the domain again, it changed to No logo…
To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…
Exchange organizations may use the Journaling Agent of the Transport Service to archive messages going through Exchange. However, if the Transport Service is integrated with some email content management application (such as an antispam), the admini…
Suggested Courses

621 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question