In some scenarios an organization will want to prevent email users from sending messages to certain external domain names.  This can be achieved with Exchange Server 2010 using a Transport Rule.

Open the Exchange Management Console and navigate to Organization Config/Hub Transport.

Block Users Sending to Specific Domains with Exchange Server 2010

Start a New Transport Rule.  Give the rule an appropriate name and description.

Block Users Sending to Specific Domains with Exchange Server 2010

Choose conditions of “From users that are inside the organization” and “When a recipients address contains specific words“.  Click on “specific words” and add the domain name you want to block, for example “@fabrikam” (without quotes).  You can enter several domain names in this list.

Block Users Sending to Specific Domains with Exchange Server 2010

Click Next and choose actions of “Send rejection message to sender…“.

Block Users Sending to Specific Domains with Exchange Server 2010

Enter a rejection message and an enhanced status code so that the sender or the IT admins can easily tell why the email was rejected.

Complete the Transport Rule wizard and test the new rule by trying to send an email to that domain name.

Block Users Sending to Specific Domains with Exchange Server 2010

You should now receive a bounce message from the Exchange server with the text that you configured.

Block Users Sending to Specific Domains with Exchange Server 2010

About the Author

Paul Cunningham

Paul is a former Microsoft MVP for Office Apps and Services. He works as a consultant, writer, and trainer specializing in Office 365 and Exchange Server. Paul no longer writes for Practical365.com.

Comments

  1. Navaid

    Hi Paul,

    I am working on Exchange Server 2010. In my company, I get 1 or 2 complaints every months that the client can not send mail to us. I would like to know how to add an email address or a domain in a white list if it’s blacklisted.

    Thanks

  2. Gaurang Patel

    Thank you, it helps 🙂

  3. Ram

    My requirement is restrict user a, user b, etc. User a only allowed to abc@abc.com

    User b only allowed to @delt.com users c only allowed to abc@abc.com and @delt.com

    This list will be in cvs file.

    Is there a way to automate and update on regular basis

  4. Pravin

    Thanks Paul

  5. Dennis Buck

    Perfect!
    Works when trying to prevent users from replying to email scams.

  6. Jason

    Thanks Paul – you the man!

  7. MOHAMMED SHUJATH

    Very Thanks a lot Paul

  8. Kirld

    Hi Paul,

    We have a requirement to disallow some users to sending to all domains except 2 domains. i have created a transport rule for that but if i put in the recipient list the combined allowed and restricted domains, it will go thru without being stopped by the transport rule.

    Please advise.. Thanks

  9. Samiuddin

    Thanks Mr. Paul for your contribution, the published article is very handy & helpful.

    Good going keep it up

  10. Syed Irfan Ali

    We have a situation where we need to restrict number of users to be able to send/receive emails from two particular domain.
    Please suggest how can this be setup!

    1. Syed Irfan Ali

      in Exchange 2010

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