Folks, This is information for other users - I already have the solution. I've been working on a script that creates shared mailboxes for my company, and when I was granting send-on-behalf permissions to more than one user, only the last user retained the permission. I did the required searching, and found the forum threads saying this was a multi-valued field and that only the last submission was retained. This got me thinking, and for my issue, I came up with the following PowerShell code for solution: $SavSndBhlf = (Get-Mailbox $NewMbx -DomainController $DomCtrl).GrantSendOnBehalfTo $SendBehalf | % { $SavSndBhlf.Add($(Get-Mailbox $_.Alias).Identity) } Set-Mailbox $NewMbx -GrantSendOnBehalfTo $SavSndBhlf -DomainController $DomCtrl " These rights are currently granted to ..." Get-Mailbox $NewMbx -DomainController $DomCtrl | % { $_.GrantSendOnBehalfTo } | Ft Name -HideTableHeaders In this, $NewMbx is the new mailbox I just created, and $SendBehalf is a list of mailboxes that I am granting send-on-behalf permissions. I include the domain controller so I won't need to worry about AD replciation in the rest of my script. In this script, I first get the current list of accounts or groups with Send-On-Behalf permissions (which on a new mailbox is empty, but this allows me to reuse this same code for updating the same information on existing mailboxes). Next, I add the new accounts to that list. Then I place the last back on the new mailbox with the Set-Mailbox command. All in all, it worked out fine for me. This same logic can be used for updating any multi-valued field that won't accept new values to the list - such as Distribution Group membership. HTH ... Will Martin

You don't need to do all of that. See this article: http://technet.microsoft.com/en-us/library/bb684908 Multivalue property syntax Action Syntax Add one or more values to a multivalued property @{Add="<value1>", "<value2>", "<value3>"} Remove one or more values from a multivalued property @{Remove="<value1>", "<value2>", "<value3>"} Mike Crowley | MVP My Blog -- Planet Technologies

Hi Guys, Thanks for sharing. Regards, Simon

Mike, Thanks for the update! This simplifies my script above to the following: $SendBehalf | % { Set-Mailbox $NewMbx -GrantSendOnBehalfTo @{Add=$_} -DomainController $DomCtrl } " These rights are currently granted to ..." Get-Mailbox $NewMbx -DomainController $DomCtrl | % { $_.GrantSendOnBehalfTo } | Ft Name -HideTableHeaders And you can do much the same thing for removing permissions from a list of accounts. Will Martin

You weren't asking a question, but instead offering help, so I changed the thread to a comment. If you'd like to change it back, click "change type". Mike Crowley | MVP My Blog -- Planet Technologies

True, but the thread was still submitted as a question.

As I said, you're welcome to change it back. What is your question? Mike Crowley | MVP My Blog -- Planet Technologies

I see - you had changed it. I have now marked it as a question, and I marked the responses I felt were the answers people would want to see. THanks, Mike