Forum Discussion

Biju Daniels's avatar
Biju Daniels
Copper Contributor
May 10, 2018

O365 Group and Distribution Group Cannot recieve Email from External

Created a Group in O365 and also a Distribution Group in O365. We have a Hybrid environment.   Cannot Email from External Email Address   This is the Error   This is the Email Security Gateway ...
microsoft 365 groups
office 365
VasilMichev's avatar
VasilMichev
MVP
May 10, 2018

As the NDR message suggests, you probably have some incorrect setup with your mail flow, causing a loop. As you haven't provided any details with respect to where the MX record point at, how connectors are configured and so on, we can only advise you to check your configuration. You can always open a support case to get this properly investigated.

  • Biju Daniels's avatar
    Biju Daniels
    Copper Contributor
    May 11, 2018

    I just sent a Private Message to Michev

    We have a Barracuda Device and mx records points there and Barracuda will accept emails from both.

     

    Only O365 Groups and DG has issue. Cannot recieve emails from pn-prem users and external users.

    O365 users can sent emails

    • Anonymous's avatar
      Anonymous
      Mar 28, 2019

      Biju DanielsHi there, Did you find a resolution?

      I am in the same boat. My mail flow is fine for On-Prem user to 365 users/shared mailboxes but I get an NDR for mail loop when an on-prem users sends an email to a 365 DL or Group.