How to Customize Responses to E-Mail Rejected by an IP Block List

Exchange 2007

Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1

Topic Last Modified: 2009-05-04

In Microsoft Exchange Server 2007, when you send an e-mail message from a computer whose IP address resides on a Block IP List, you receive the following error message:


550 5.7.1 Recipient not authorized, your IP has been found on a block list.

If want to provide more detail in the error message, you can change the default message to include the following information:

  • IP address of the sending Mailbox server

  • Rule name of the connection filter

  • The Real-time Block List Provider

To change the default message response
  • From the Exchange Management shell, use the following syntax to customize the Block List response:

    Set-IPBlockListProvider -Identity <providername>  -RejectionResponse: "My custom response {0}, your text {1}, more text {2}"

    Where the following is true:

    {0} = IP address sent in the query

    {1} = IP Block List Provider Name

    {2} = Lookup Domain (provider.LookUpDomain)


    For example, use the following syntax:

    Set-IPBlockListProvider - Identity Contoso -RejectionResponse: "Your message was rejected because the IP address of the sending server {0} is blacklisted by {1} Lookup Domain {2}"

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