Exchange 2013: Send/Receive connectors broken


  • I am experiencing difficulties with my send and receive connectors in Exchange 2013.

    We have had big issues with our Exchange, but I managed to reinstall Exchange 2013 (CU1) and recover the database.

    Now, I have the problem that:

    - Outlook (client) can not connect to the server.

    - I can not send messages OUT (using OWA)

    - I can not receive messages. Telnet to external interface port 25 returns "421 4.3.2 Service not available". (Yes, anonymous authenticaction is ON and binding on IP

    Also, NO Anti-Virus is running, Mailware checking has been disabled and when I telnet to the WAN interface ON THE SAME MACHINE, I *DO* get a telnet port 25 reply...

    I have tried everything. Link DNS servers to outgoing interface, reset Certificates, recreate connectors. No Luck.

    I am thinking my send and receive connectors are somehow damages. Is there a way I can delete them and let exchange recreate the default ones using some sort of powershell script?

    What can we do here?

    Can anyone help?

    Wednesday, September 04, 2013 7:45 PM


All replies

  • I managed to get receive connector working, by completely resetting the certificate used for SMTP.

    I removed old and generated new, applied it to POP, IMAP, SMTP and IIS.

    However, my Outlook clients still can't connect, and outgoing E-Mail does not work.

    Anyone any idea?

    Wednesday, September 04, 2013 9:57 PM
  • The domain I am sending TO is OK.. gmail, Hotmail, whatever... they all are fine.
    The problem is internally in the exchange.
    The queues are empty. I see that.

    The send connector is created, as per instructions all over the web.
    Still when I send an email using OWA, when clicking send it goes to "DRAFTS".
    Outlook client seems to freeze entirely...

    I can't even send mail OUT internally! So not only externally, even internally!
    With OWA, it just sits there in  "Drafts"

    Receiving mail is not a problem (from outside).

    • Edited by snigavig1 Friday, September 06, 2013 7:13 AM
    Thursday, September 05, 2013 9:32 PM
  • Your server probably does not have enough disk space or RAM. It looks like Transport is in back pressure and is rejecting inbound anonymous connections (421 4.3.2 Service not available).

    Lack of RAM is probably the reason why OWA is not working and Outlook is not connecting. Start with at least 12GB of RAM on the box and work upwards from there.

    Send/Receive connectors do not cause OWA/Outlook to fail. Check that all the services are running that should be.

    You don't need to change the connectors in 2013 to make it work (unlike 2010 where you needed to set anon on a receive connector). You do need a send connector if you have not upgraded a 2010 environment.


    Brian Reid C7 Solutions Ltd (

    Friday, September 06, 2013 1:55 PM
  • Hi,

    1. Please do RCA first.

    For your convenience:

    Remote Connectivity Analyzer


    2. Please collect NDR information when failing to send emails.

    About the NDR, please see:

    DSNs and NDRs (applies to Exchange 2013 server)


    3. Please try Protocol Logging.

    Protocol logging records the SMTP conversations that occur between messaging servers as part of message delivery.

    We can use protocol logging to diagnose mail flow problems.

    More details in the article below:

    Protocol Logging




    Tuesday, September 10, 2013 8:03 AM