Microsoft Outlook: Delivery has failed to these Recipients or Groups

Our customer recently switched to Microsoft’s Office 365 exchange service as their email provider. Previously to this transition, this company was hosting their own exchange server. After the upgrade some of the employees would get an error message when emailing within the organization.  Here is the message:Outlook Errorscreenshot.bmpscreenshot


The email address you entered couldn’t be found. Please check the recipient’s email address and try to resend the message. If the problem continues, please contact your helpdesk.  Outlook ErrorOutlook Error


The email addresses didn’t change during the upgrade to Office 3Outlook Error65. The users were correctly entering the email addresses as well.

So the first thing to try is to delete the autocomplete in Outlook. When you enter the recipient in Outlook , delete the autocomplete suggestion that pops up.


See if that fixes the issue, it didn’t for me .

I then downloaded this NK2View tool from here. I ran this cool little utility and it brought up the autocomplete cache. I scrolled down to the email recipient my customer was having trouble emailing and deleted that entry. I then tried sending a test email and it worked like a charm.

Resolution: When I used the NK2View utility to delete the entry it actually deleted the autocomplete entry for real. Apparently, when they were trying to email within the organization the autocomplete had saved some information about their previous email servers and was trying to deliver the message to the old server. I just deleted the autocomplete entry and everything was fine.

This was posted by techspeeder.

5 thoughts on “Microsoft Outlook: Delivery has failed to these Recipients or Groups

  1. Lee

    I’ve tried your solution and it worked on one computer. However it didn’t work on another computer. I deleted the auto-complete address but still not resolved.

    1. Merlin Halteman Post author

      Hello Lee, Thank you for sharing. I know this sounds like a dumb troubleshooting step, but sometimes it is easy to overlook the simplest problems. I would double check the spelling of the email address you are trying to send to. Also make sure it is a valid address. If you are still receiving that bounce back error, you could try creating a new profile in Outlook. Please post back with your findings. Thanks

  2. Keyur Patel

    Bro am having the same errors. checked yours dumbest of steps very first. But still can’t get going on.

  3. Pingback: Delivery Has Failed To These Recipients Or Groups –

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