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Messages not using correct ReceiveConnector RRS feed

  • Question

  • Greetings,

    I know the relay questions get asked a lot and this is why I tried to follow what is stated in several other questions and followed the advice https://practical365.com/exchange-server/exchange-2016-smtp-relay-connector/

    We have an app that is trying to relay messages outside our organization. It works perfectly in Exchange 2010. However when moved to Exchange 2016, even using a copy of the same connector with the same properties, it tries sending to to the default connector. The app is using anonymous authentication. Other applications seem to have no issue and are set in the relay connector.

    I tried renaming the connectors so if I telnet, I can see which connector is responding but so far they seem to be only using the default one.

    The default connector is set up as follows:

    AuthMechanism                             : Tls, Integrated, BasicAuth, BasicAuthRequireTLS, ExchangeServer
    Bindings                                  : {[::]:25, 0.0.0.0:25}
    RemoteIPRanges                            : {::-ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff, 0.0.0.0-255.255.255.255}
    TransportRole                             : FrontendTransport
    PermissionGroups                          : AnonymousUsers, ExchangeServers, ExchangeLegacyServers

    I have tried different combinations none work:

    AuthMechanism                             : Tls, 
    Bindings                                  : {0.0.0.0:25}
    RemoteIPRanges                            : (list of internal IPs)
    TransportRole                             : FrontendTransport
    PermissionGroups                          : AnonymousUsers, ExchangeServers
    
    

    I have both set up to log but I see connections only to the default connector. I'm wondering if I need to change something in the default connector but if i do, email fails.

    Another issue I'm finding is that in Exchange 2010 the email is sent using the name of the user, not the address, for example: John Clark - jclark@enterprise.com. It used to send emails from 'John Clark' when you received them. Now the name is gone with Exchange 2016 and you receive emails like jclark@enterprise.com and they get questioned if they are SPAM.

    Could you help me?

    Monday, February 11, 2019 6:18 PM

Answers

  • So from the relay source, when you do a telnet to the Exchange & ehlo.. do you see the right IP of the source listed?

    What verbs do you see after ehlo..

    Regards,

    Fazal


    Disclaimer: The views expressed on this blog are my own and do not necessarily reflect the views of my employer.

    • Marked as answer by Eve_K Friday, February 15, 2019 5:31 PM
    Monday, February 11, 2019 8:38 PM

All replies

  • Connections would normally hit the default connector if the source IP is not allowed on the relay connector, Is the correct IP listed? ... Are there multiple IPs for the application or NATing.. 

    Regards,

    Fazal


    Disclaimer: The views expressed on this blog are my own and do not necessarily reflect the views of my employer.

    Monday, February 11, 2019 8:00 PM
  • I have the IP listed in the 'relay' connector. As far as I know it only uses that IP.
    Monday, February 11, 2019 8:26 PM
  • So from the relay source, when you do a telnet to the Exchange & ehlo.. do you see the right IP of the source listed?

    What verbs do you see after ehlo..

    Regards,

    Fazal


    Disclaimer: The views expressed on this blog are my own and do not necessarily reflect the views of my employer.

    • Marked as answer by Eve_K Friday, February 15, 2019 5:31 PM
    Monday, February 11, 2019 8:38 PM
  • Hm this is curious. I had never really noticed the IP it replies is the load balancer IP. Therfore, all the IPs are the same.

    Exchange 2016
    220 EXCHANGESERVER\Default Frontend EXCHANGESERVER
    ehlo
    250-EXCHANGESERVER.domain.com Hello [IP OF KEMP LOAD BALANCER]

    Thank you. Let me investigate this further. I can't believe I didn't notice before.

    Monday, February 11, 2019 9:10 PM
  • Hi,

    Do you investigate the relay application settings? Is there any update?

    Besides, could you please share the settings of the custom relay connector?

    Get-ReceiveConnector <connector name>|fl

    Regards,

    Dawn Zhou


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    Thursday, February 14, 2019 9:56 AM
  • It's related to the load balancer, we need to set up transparency but for this there has to be some changes to the network.

    I may have the answer but I'm still investigating.

    Thank you. I will mark an answer now.

    Friday, February 15, 2019 5:31 PM