• Twitter
  • FaceBook

Exchange Server Forums

Forums | Register | Login | My Profile | Inbox | RSS RSS icon | My Subscription | My Forums | Address Book | Member List | Search | FAQ | Ticket List | Log Out

Can't receive mail, but can send!!

Users viewing this topic: none

Logged in as: Guest
  Printable Version
All Forums >> [Microsoft Exchange 2003] >> Installation >> Can't receive mail, but can send!! Page: [1]
Message << Older Topic   Newer Topic >>
Can't receive mail, but can send!! - 28.Jun.2006 3:50:44 PM   


Posts: 1
Joined: 28.Jun.2006
Status: offline
Hello everyone, I just joined the forum because I'm having an issue with exchange 2003, DNS, and possibly a firewall.

This is a pretty routine set up, so I am sure someone else out there has had this problem and I'm hopeful that we can get it resolved!

I have an inside network at lets say with a PDC, backup domain controller, file server, and wsus/print server.

I have a DMZ with 2 servers.  The exchange 2k3 server is located here and a web server.  Lets say that is my web server and is my mail server.

Lets say that the firewall is

And finally, lets say that traffic comes in from

What would my mx record in exchange would point to??  What else would I need in dns?

Currently I can send mail out internally and receive it back, but when I send mail out to the world it is received but when they reply I do not receive it.

I know - it sounds like a firewall problem but I have had all of that checked and he assured me that it was working properly (able to telnet to the mail server).

So assuming that all the firewall stuff is running where do I go from here?

If you need any other info please let me know!

Thank you!

Post #: 1
RE: Can't receive mail, but can send!! - 28.Jun.2006 5:30:36 PM   


Posts: 8232
Joined: 7.Jan.2004
From: California, USA
Status: offline
Your MX record must point to something capable of either receiving or forwarding SMTP (port 25) traffic.  If you are receiving newly created messages (non-replies), your MX record is likely correct.  If you are not receiving any messages, check to see at the listed address if you are receiving anything.

Your MX record is used by external mail sources (e.g. to determine where to send the message.  Are you hosting your own DNS for your domain, or using an external service?  Also, it must be a public address.  I couldn't tell if you were giving the 192.168.x.x and 10.x.x.x addresses as examples or the real addresses, but those will not work as they are not publically routable.



Dean T. Uemura
Microsoft MVP - Exchange (2007-2011)

(in reply to Sh4dow)
Post #: 2
RE: Can't receive mail, but can send!! - 28.Jun.2006 7:58:42 PM   
Richard Fleming


Posts: 85
Joined: 24.Oct.2002
From: Toronto, ONT [Canada]
Status: offline
Sh4dow... welcome aboard.

First off, let me say that your configuration is dangerous!  Having your exchange server on a DMZ is just an accident waiting to happen.

Your Exchange server should be nestled safe with your Domain controller on the 192.168 network, and an SMTP gateway should be on the DMZ.

To address your problem you need to have a firewall that uses Network Address Translation (NAT).  Your firewall has to be configured to point any mail that comes from to, and you need to have a corresponding MX record that says that all mail to your domain goes to  Lastly, make sure that the only open ports for your Exchange server (to keep you safe) are ports (SMTP) 25, (POP3) 110, IMAP4 (143) and if you use the web client port 80.  All other ports should be closed to prevent your exchange box and your domain from being compromised.

That should solve your problems.


(in reply to Sh4dow)
Post #: 3

Page:   [1] << Older Topic    Newer Topic >>
All Forums >> [Microsoft Exchange 2003] >> Installation >> Can't receive mail, but can send!! Page: [1]
Jump to:

New Messages No New Messages
Hot Topic w/ New Messages Hot Topic w/o New Messages
Locked w/ New Messages Locked w/o New Messages
 Post New Thread
 Reply to Message
 Post New Poll
 Submit Vote
 Delete My Own Post
 Delete My Own Thread
 Rate Posts

Follow TechGenix on Twitter