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Internla Application Email Replay Problem - Mailbox Unavailable. The server Response was 5.7.1. Unable To relay

    Question

  • Hi,

    We are facing issue with internal application relay issue.

    The email will be triggering normally but, suddenly it will show error as "Mailbox Unavailable. The server Response was 5.7.1. Unable To relay"

    After some time it works normally

    We are having lot of Internal application which relays through our exchange server.

    We have HLB configured and we created dedicated Service for only this relay purpose

    We will add the application server IP in the HLB to be able to relay emails from the application server

    In turn, there is a connector in exchange which allow only the HLB application relay IP in the connector

    In the connector "Anonymous" authentication is selected

    What could be the issue for this intermittent issue?


    Manju Gowda

    Tuesday, October 20, 2015 11:40 AM

Answers

  • Three things:

    1. Verify the relay is configured correctly. Example:

    http://exchangeserverpro.com/exchange-2013-configure-smtp-relay-connector/

    2. How many servers are part of this HLB pool? If more then one, ensure they are all configured correctly.

    3. Can you connect directly to the Exchange Server<s> and test rather then going through the Load Balancer?


    Twitter!: Please Note: My Posts are provided “AS IS” without warranty of any kind, either expressed or implied.

    Tuesday, October 20, 2015 12:24 PM
  • Hi manju,

    Thank you for your question.

    In the link which Andy supplied, please make sure you are choose “Fronted Transport” instead of “Hub Transport”, we could refer to the following link:

    https://social.technet.microsoft.com/Forums/office/en-US/f57ad543-2502-4770-9bfe-c11fcb6846d7/failure-sending-mail-mailbox-unavailable-the-server-response-was-571-unable-to-relay?forum=exchangesvradmin 

    Then, please make sure there is no network issue on application reply to Exchange server. We could change another application relay to check if the issue persist.

    Best Regard,

    Jim

    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Jim Xu
    TechNet Community Support

    Thursday, October 22, 2015 2:55 AM
    Moderator

All replies

  • Three things:

    1. Verify the relay is configured correctly. Example:

    http://exchangeserverpro.com/exchange-2013-configure-smtp-relay-connector/

    2. How many servers are part of this HLB pool? If more then one, ensure they are all configured correctly.

    3. Can you connect directly to the Exchange Server<s> and test rather then going through the Load Balancer?


    Twitter!: Please Note: My Posts are provided “AS IS” without warranty of any kind, either expressed or implied.

    Tuesday, October 20, 2015 12:24 PM
  • Hi manju,

    Thank you for your question.

    In the link which Andy supplied, please make sure you are choose “Fronted Transport” instead of “Hub Transport”, we could refer to the following link:

    https://social.technet.microsoft.com/Forums/office/en-US/f57ad543-2502-4770-9bfe-c11fcb6846d7/failure-sending-mail-mailbox-unavailable-the-server-response-was-571-unable-to-relay?forum=exchangesvradmin 

    Then, please make sure there is no network issue on application reply to Exchange server. We could change another application relay to check if the issue persist.

    Best Regard,

    Jim

    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Jim Xu
    TechNet Community Support

    Thursday, October 22, 2015 2:55 AM
    Moderator