Forum Discussion

Eric_H's avatar
Eric_H
Iron Contributor
Apr 29, 2019
Solved

Whitelist external senders to a 365 group

I generally want to block external email traffic to our 365 Groups.  However, we have some external systems producing alerts or updates that I want to deliver to a 365 Group.  That way users who are ...
Office 365 Groups
  • VasilMichev's avatar
    VasilMichev
    Apr 30, 2019

    You can use the standard message delivery parameters:

     

    AcceptMessagesOnlyFrom : {}
    AcceptMessagesOnlyFromDLMembers : {}
    AcceptMessagesOnlyFromSendersOrMembers : {}
    RejectMessagesFrom : {}
    RejectMessagesFromDLMembers : {}
    RejectMessagesFromSendersOrMembers : {}

VasilMichev's avatar
VasilMichev
MVP
Apr 30, 2019

You can use the standard message delivery parameters:

 

AcceptMessagesOnlyFrom : {}
AcceptMessagesOnlyFromDLMembers : {}
AcceptMessagesOnlyFromSendersOrMembers : {}
RejectMessagesFrom : {}
RejectMessagesFromDLMembers : {}
RejectMessagesFromSendersOrMembers : {}

Eric_H's avatar
Eric_H
Iron Contributor
Apr 30, 2019

VasilMichev, I had looked at this but got caught up on the external email address (the parameter only allows you to add users).  Then it occurred to me I could create a contact with the inbound email address, and add that contact to the message delivery parameters.  That works!  Thanks for the help!   For others looking, here's Microsoft's documentation on configuring delivery restrictions: https://docs.microsoft.com/en-us/exchange/recipients/user-mailboxes/message-delivery-restrictions?view=exchserver-2019

And if using powershell, you have to use "set-unifiedgroup" commands instead of "set-mailbox", but the concept is the same.  

Resources