Unable to Find Users When Configuring Distribution Group Delivery Restrictions

In Easy365Manager, you can configure delivery restrictions on distribution groups via the Office 365 tab on the distribution group:

Configure distribution group delivery restrictions with Easy365Manager

In some cases, you can’t find the recipient you want to add to the delivery restrictions when clicking add and searching for a user.

At the same time, when you configure delivery restrictions on mailboxes, you are perfectly able to find and select the recipients.

This issue is caused by the fact that the member lists for delivery restrictions are populated differently for users (mailboxes) and distribution groups.

For users (mailboxes), this is configured directly on the Exchange Online mailbox. The delivery restrictions member list on Exchange Online mailboxes references Office 365 objects.

For hybrid (synchronized) distribution groups, the delivery restrictions member list is configured on the AD group object (and synchronized to Exchange Online). Therefore, the distribution group delivery restrictions member list references mail-enabled (on-premises) Active Directory objects.

The solution to add the missing recipients to the distribution group delivery restrictions member list is to ensure that the recipients are properly mail-enabled in the on-premises Active Directory.

You can verify if an on-premises user is properly mail-enabled in the on-premises Active Directory by running the following command:

Get-ADUser [user name] -Properties * | fl Name,mailNickname,proxyAddresses

The output should be similar to this:

Name                       : Lene Hau
mailNickname               : lene.hau
proxyAddresses             : {smtp:lene.hau@e365m.skrubbeltrang.com, SMTP:lene.hau@azure.skrubbeltrang.com,
                             smtp:lene.hau@e365m.onmicrosoft.com, smtp:lene.hau@e365m.mail.onmicrosoft.com}

If mail attributes are missing, you can easily configure them with Easy365Manager:

How to configure the email alias (nickname).

How to configure the email addresses (proxyAddresses).