Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Exchange wont send email to particular domains

Posted on 2014-03-18
6
Medium Priority
?
584 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
New Tabletop Appliances Blow Competitors Away!

WatchGuard’s new T15, T35 and T55 tabletop UTMs provide the highest-performing security inspection in their class, allowing users at small offices, home offices and distributed enterprises to experience blazing-fast Internet speeds without sacrificing enterprise-grade security.

 
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

Creating Active Directory Users from a Text File

If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.

Question has a verified solution.

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

As much as Microsoft wants to kill off PST file support, just as they tried to do with public folders, there are still times when it is useful or downright necessary to export Exchange mailboxes to PST files. Thankfully, it is still possible to e…
Mailbox Corruption is a nightmare every Exchange DBA wishes he never has. Recovering from it can be super-hectic if not entirely futile. And though techniques like the New-MailboxRepairRequest cmdlet have been designed to help with fixing minor corr…
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
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

916 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