locked
Yet another 550 5.7.1 Unable to relay question. RRS feed

  • Question

  • I started out with a working Exchange 2003 environment, and have successfully added an Exchange 2010 server.  It's a small emplacement so the server is running all roles.  I have created a dual function receive connector between 2003 and 2010 and it all works fine.  However Exchange 2010 didn't use the 2003 frontend internet gateway that has worked for years so I decided to add the edge server.

    Taking this to the next step for mail flow I eagerly wanted to add an edge server to replace my frontend 2003 server.  

    I built a windows 2008 R2 box (this all done on Hyper-V BTW) where I loaded the Edge role successfully.  Knowing I needed the ADAM function and all it's glory, I loaded it and precoded to create an edge subscription between the HUB role and this new edge server.

    This too worked fine as running the edge sync returned successful sync on both the internal server and Edge server. 

    At this point I saw the two "edgesync" send connectors and figured all was ready to do internet mailing. 

    Now, I open outlook and send to my hotmail account and receive an NDR with the dreaded 550 5.7.1 unable to relay.  Knowing this is usually a permissions issue I proceeded to further test and tinker to feel out what was happening and why my edge server didn't relay to the internet.

    Long story short, it occurred to me that I hadn't done anything to build a relay or gateway server on this edge server so maybe I had skipped a few steps.  I looked on the internet for guidance and they all say basically the same thing, and that is to build the server and do the edge subscription and poof!  But nothing seemed to work as that here.  

    I have now taken my edge server down to simply the edge role, and removed the subscription on both the HUB server and edge server rendering the edge server to simply a smart host.

    At this level I know I need both a send and receive connector so have built them, and have successfully tested inbound email to it but of course it can't yet pass into the hub server.

    The ultimate problem is when I try to send out, I consistently receive unable to relay, and I'm totally baffled on such a simple problem.  DNS is the same as I was using for 2003, and it works fine.  

    I also can use telnet to port 25 and generate outgoing messages, and when I use the rcpt to: command to any outside domain, I receive simply 550 5.7.1 Unable to relay.  

    I'm about out of hair now, but any advice would be helpful!

     

    Thank you!

    Monday, January 24, 2011 6:21 PM

Answers

  • Thank you Clint.

     

    I followed all these steps, and had done so before.  I finally got things to work by using basic logic and stepping through the processes of mail delivery (using the items you suggested as well).  What I wasn't clear on (and maybe still confused with) is that the edge subscription is only part of the vehicle in connecting the hub servers to the internet via an Edge server!  What I mean is I read many articles outlining the process of creating the edge subscription, but that seemed to be the end of the story.  

    What I ended up having to add to that was 2 receive connectors!  one implicitly for the internal servers to talk to the Edge, and the other for inbound from the internet.  the moment I created the edge server "send connector" all of my messages queued on the hub server went!  

    Next I tested inbound messaging and was still receiving failures, so with the same logic I added an internet inbound receive connector, and poof!  

    I have to say I'm concerned now that these two receive connectors are still not right, but they work and for now I'm content.  

    I have to say I'm disappointed in all the documentation that leads me to believe the edge subscription is all that is needed but after recreating that a second time, the edge server reacted as if port 25 wasn't even turned on.

    Anyway I hope this might be of help to others out there and if what I have done was wrong, please let me know that too!

     

    Thanks again Clint for your help!  big time Thanks!

     

    • Marked as answer by SG_Dan Saturday, January 29, 2011 8:13 PM
    Saturday, January 29, 2011 8:13 PM

All replies

  • Have you created an SMTP send connector ?

    http://technet.microsoft.com/en-us/library/aa997285.aspx

    These are needed for Exchange to send email externally.  They need to be created on the hub transport server and will get replicated using ADAM or LDS to your edge.  From the server that will pass email out to the internet, can you telnet other mail servers on the internet on port 25?

    The 550 5.7.1 Unable to relay  is generated whenever an Exchange server recieves an email and doesnt know what to do with it!


    Clint Boessen MVP - Exchange Server, MCSE, MCITPx4, Dip Network Engineering
    Perth, Western Australia

    Blog: http://clintboessen.blogspot.com/
    Tuesday, January 25, 2011 4:45 AM
  • Clint,

    Thanks for your reply!  The steps I took first were to create the edge sync or edge subscription, which I understood created the necessary send connector for internet mail.  Even in the article you reference, it suggests that the edge sync process creates the necessary send connector.  

    My question now is, once I regenerate the edge subscription, will I then need to also create (On the HUB server I assume) another internet send connector?

    currently I removed the edge subscription and have been trying just to get the edge server to act as a simple relay or smart host as part of my trouble shooting, all of which have resulted in ultimately generating the Unable to relay.  

    That said, I'm unsure that my edge server is configured correctly or that it knows how to route mail to the internet, and what I need to do to get at least that.  Maybe what your suggesting will bypass all that and create the necessary connectors?

    Thanks again!

     

    Tuesday, January 25, 2011 3:57 PM
  • The following connectors are required on the Edge Transport server:

    • A Send connector configured to send messages to the Internet
    • A Send connector configured to send messages to the Hub Transport servers in the Exchange organization
    • A Receive connector configured to receive messages only from Hub Transport servers in the Exchange organization
    • A Receive connector configured to accept messages only from the Internet

    Please follow step 1 to 4 on the following URL:

    http://technet.microsoft.com/en-us/library/bb232082.aspx

    Also ensure from the edge transport server you can telnet outbound SMTP servers on port 25.  Try hotmail:

    telnet mail.hotmail.com 25

    If you are still experiancing issues please enable verbose SMTP protocol logging and have a look which connector the email is failing at.

    http://clintboessen.blogspot.com/2009/06/exchange-2007-smtp-protocol-logging.html


    Clint Boessen MVP - Exchange Server, MCSE, MCITPx4, Dip Network Engineering
    Perth, Western Australia

    Blog: http://clintboessen.blogspot.com/
    • Proposed as answer by Clint Boessen Thursday, January 27, 2011 1:29 AM
    Thursday, January 27, 2011 1:28 AM
  • Thank you Clint.

     

    I followed all these steps, and had done so before.  I finally got things to work by using basic logic and stepping through the processes of mail delivery (using the items you suggested as well).  What I wasn't clear on (and maybe still confused with) is that the edge subscription is only part of the vehicle in connecting the hub servers to the internet via an Edge server!  What I mean is I read many articles outlining the process of creating the edge subscription, but that seemed to be the end of the story.  

    What I ended up having to add to that was 2 receive connectors!  one implicitly for the internal servers to talk to the Edge, and the other for inbound from the internet.  the moment I created the edge server "send connector" all of my messages queued on the hub server went!  

    Next I tested inbound messaging and was still receiving failures, so with the same logic I added an internet inbound receive connector, and poof!  

    I have to say I'm concerned now that these two receive connectors are still not right, but they work and for now I'm content.  

    I have to say I'm disappointed in all the documentation that leads me to believe the edge subscription is all that is needed but after recreating that a second time, the edge server reacted as if port 25 wasn't even turned on.

    Anyway I hope this might be of help to others out there and if what I have done was wrong, please let me know that too!

     

    Thanks again Clint for your help!  big time Thanks!

     

    • Marked as answer by SG_Dan Saturday, January 29, 2011 8:13 PM
    Saturday, January 29, 2011 8:13 PM