I've the following issue: I've created 5 users with custom attribute 1 as 12345 and a dynamic distributiongroup Numbers. Members of this distribution group are all users with cutom attribute 1 as 12345. the PS commands are:Set-Mailbox -Identity test01 CustomAttribute1 12345Set-Mailbox -Identity test02 CustomAttribute1 12345Set-Mailbox -Identity test03 CustomAttribute1 12345Set-Mailbox -Identity test04 CustomAttribute1 12345Set-Mailbox -Identity test05 CustomAttribute1 12345 new-DynamicDistributionGroup -Name 'Numbers' -IncludedRecipients 'AllRecipients' ConditionalCustomAttribute1 '12345' -OrganizationalUnit 'contoso.com/Groups/Distributiongroups' -Alias '12345' -RecipientContainer 'contoso.com' Set-DynamicDistributionGroup -Identity 12345 -ManagedBy Groupmanager Set-DynamicDistributionGroup 12345 -GrantSendOnBehalfTo Groupmailer Set-DynamicDistributionGroup -Identity 12345 -RequireSenderAuthenticationEnabled $False It works more or less good. all emails are distributed to all members. also from extern.but: problem 1:is it possible to grant the send as permission the created dynamic distribution group or a whole group? so that i can join user 6 to the group an he gets autimatically the send as permission.problem 2:the groupmailer is able to send mails as Numbers from pc 1, but not from pc2.

Hi,You can give the Send On Behalfof the DynamicDistributionGroup permission to one group (group1), thenthe userwill be obtained the send as permission once it is added into group1.ThanksAllen

Hi Allen, thanks for your reply. And how can I do that? Set-DynamicDistributionGroup 12345 -GrantSendOnBehalfTo group1@contoso.com or which syntax? Which kind of group it has to be? Security, Distribution... eMail activated... Bastian

Hi,I have tested on the lab, the permission could not be given for the group. After further researching on this issue, I found the GrantSendOnBehalf only support a mailbox user. Sorry for the wrong direction previously.Thus, there is no workaround for your issue.ThanksAllen

The "Send as" Permission is an ADsecurity principle, and only a user object or security group (email enabled or not)can hold this permission.Standard and Dynamic distribution groups cannot hold AD security principles.You can converta normalmail-enabled distribution group into a mail-enabled security group using ADUC,but you cannot do this with a Dynamic Distro group.Deaton