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How to reject emails which are sent to email addresses which don't exist on our domain

    问题

  • Hello,

    Where can I set our mail server to reject any emails which are sent to email addresses which do not exist on our domain?

    For example, if I have only these 3 email addresses on my domain:

    bob@horse.com

    amy@horse.com

    ted@horse.com

    When a customer sends an email to blahblah@horse.com, I want them to get a bounce back message so that they know they have sent an email to an incorrect address (which ultimately will never be read by anyone). Presently, they don't receive this bounce back message and so assume that our company has received the email.

    Thanks in advance,

    Michelle


    • 已编辑 Michelle99 2018年5月11日 10:00 better heading
    2018年5月11日 10:00

全部回复

  • https://social.technet.microsoft.com/Forums/exchange/en-US/62e759ef-3716-4f22-b09c-259c979bc687/exchange-2010-how-to-configure-ndr-for-users-that-do-not-exist-in-organisation

    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    2018年5月11日 18:00
  • Hi Michelle99,

    You can create a transport rule block mails which are send to an external user, then replay a explanation:

    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

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    2018年5月14日 10:53
  • Hi Michelle99,

     

    Any update now?

    If the above suggestion helps, please be free to mark it as answer for helping more people.


    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    2018年5月17日 3:06
  • Hi Kyle

    Apologies for the delayed reply. I actually just left things as they are - I got advised that since we get so many emails to a users which do not exist blablah@ourdomain.com horsedogcat@ourdomain.com etc... that if I formulated a bounce back message I'd clog this system up with the amount of bounce messages I'd be sending. It's not at all my area of expertise - so I erred on the side of caution - and left it running has it as been for the past few years. :-|

    But now that I re-read the link above (exchange 2010 - how to configure ndr for users that do not exist in organisation) :

    ----

    QUOTE:

    On Wed, 5 Jan 2011 12:45:47 +0000, Fizzmo wrote:
    > Want to set up an auto reply to anyone sending emails to users who do not exist in my organisation. How is this done in Exchange 2010?
     
    Don't do that. Just enable recipient filtering and reject any
    addresses that aren't in your directory. You'll find your server

    pretty swamped with undeliverable NDRs if you try to do what you said.

    ----

    That really makes sense to me as a good solution. Except - what happens to those emails which get rejected?  Our Exchange server downloads email from a "catch all" mailbox from an online service provider. If the emails get rejected, then I imagine they stick around in this mailbox.

    Perhaps.. is it possible to automatically delete any email messages received on Exchange Sever which are address to a "non existant" recipient (Eg no-such-user@ourdomain.com) ?




    2018年6月13日 2:44
  • First, an Edge Transport role server is required for recipient filtering.

    https://technet.microsoft.com/en-us/library/aa995993(v=exchg.141).aspx


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    2018年6月13日 18:20