Hi,
By default, we cannot modify the recipient filter of default GAL. To temporarily modify the default GAL, please refer to the following steps:
1. Open the ADSI Edit, and expand each of the following items:
Configuration Partition | CN=Configuration | CN=Services | CN=Microsoft Exchange | CN=<Organization Name> | CN=All Global Address List | CN= Default Global Address List
2. Right click Default Global Address List and set the msExchRecipientFilterFlags value to 0.
3. Run the command:
set-globaladdresslist -identity "Default Global Address List" -recipientfilter {((Alias -ne $null) -and
(Company -ne "exclude") -and ((ObjectClass -eq 'user') -or (ObjectClass -eq 'contact') -or (ObjectClass -eq 'msExchSystemMailbox') -or (ObjectClass -eq 'msExchDynamicDistributionList') -or (ObjectClass
-eq 'group') -or (ObjectClass -eq 'publicFolder')))}
4. After that, change the attribute msExchRecipientFilterFlags value to 3.
Best Regards.