Powershell 2: Add multiple members to distribution group with one call?

I'm not sure why you don't want to use a loop construct; that's kinda one of the major features of PS. A simple:

Import-CSV FileName.csv | ForEach {Add-DistributionGroupMember -Identity "GROUP-NAME" -Member $_.Name}

would easily do the trick. Failing that, though, there's no cmdlet to do exactly what you want. You could do a

Remove-DistributionGroup GROUP-NAME; New-DistributionGroup -Name GROUP-NAME -Members memberlist

but that's a little cheesy.

I know this is an old post, but it's still the #1 result on Google when trying to find how to add multiple users to a DL so I figured I'd post my solution.

The previous solutions will work fine for a small list of users, but as the original poster stated there are performance and scaling issues with calling Add-DistributionGroupMember for every member when dealing with large membership changes, and this is compounded when dealing with O365.

To solve these issues you can use Update-DistributionGroupMember to replace the entire membership of a DL instead of adding them one by one.

e.g. for the original request you would do this:

Update-DistributionGroupMember -Identity GroupName -Members user1@domain,user2@domain,usern@domain

or

Update-DistributionGroupMember -Identity GroupName -Members $ArrayOfMemberEmailAddresses

This does replace the membership of the DL, so if you wanted to maintain the existing membership you would need to retrieve it first using Get-DistributionGroupMember then create an array of the existing members and new ones and give that to Update-DistributionGroupMember like the following:

$NewMembers = Get-Content <path to member list text file>
$CurrentMembers = (Get-DistributionGroupMember -Identity GroupName).PrimarySmtpAddress | where {$_ -ne ""}
$NewMemberList = $CurrentMembers + $NewMembers
Update-DistributionGroupMember -Identity GroupName -Members $NewMemberList -Confirm:$false

Lastly, if you're trying to update the membership on a ton of DLs in O365 like I needed to, then you can add the -AsJob switch to the Update-DistributionGroupMember command in your loop so that it runs all the updates in parallel rather than waiting for each membership update to finish before moving on. This will vastly speed up your script, but make sure you do some reading on PowerShell remoting and using Jobs first if you aren't familiar with them yet as there is some additional work you'll need to do afterwards to get the results, check for errors etc.

Doing it this way instead of using Add-DistributionGroupMemberreduced the number of commands sent to O365 for my DL migration from somewhere around 150K to about 2.5K and reduced my script runtime from multiple days to an evening for migrating the membership of 1200 DLs.

Successfully populated a Distribution Group by creating a text file, populating with member account aliases, then executing the command:

% Get-Content <path\filename.txt> | Add-DistributionGroupMember "<Display Name of Distribution Group>"

See these URLs for further details:

• http://technet.microsoft.com/en-us/library/aa995970(v=exchg.141).aspx
• http://technet.microsoft.com/en-us/library/bb125256(v=exchg.141).aspx

Not sure why the teams at Microsoft made this so complicated. Sometimes you just have to think simple.

"user1","user2","user3" | Add-DistributionGroupMember -Identity "SomeMailbox"

Try this, it seems to work for me:

Get-Content | Add-DistributionGroupMember

Text file just contains the aliases of the users that you want to add.

It looks like the Quest Active Directory PowerShell Cmdlets can add multiple users to a group at one time per this wiki page. In my brief testing, I was able to use the Add-QADGroupMember cmdlet to add a small array of users to a test group in Active Directory.

It might be helpful too to add AD with this:

import-module ActiveDirectory

Then just use:

Add-AdgroupMember MyList -member user.alias,user2.alias,user3.alias,...

For this you do need RSAT installed (MS product, and free) or it won't work.

If performance is a concern Add-ADGroupMember is by far the fastest, and as mentioned can take an array as input to the -Member parameter.

Something like that, not sure if this is well-written or working - just an idea.

Function Add-DistributionGroupMembers_Safe {
Param (
    [Parameter(Mandatory=$true)]
    [String]$Identity,
    [Parameter(Mandatory=$true)]
    [String[]]$Member
)
    $local:groupADSI = [ADSI]"LDAP://${$(Get-DistributionGroup -Identity $Identity).DistinguishedName}"
    $local:DGUsers = @( @( Get-DistributionGroupMember -Identity $Identity ).Name )
    $local:UsersToAdd = @( $Member | Where-Object { $local:DGUsers -notcontains $_ } | ForEach-Object { return (Get-ADUser -Name $_}).DistinguishedName )
    ForEach ($user in $local:UsersToAdd) {
        try {
            $local:GroupADSI.Properties["member"].Add($user) | Out-Null
        } catch {
            #Error processing, text in $_.Exception.Message
        }
    }
    $group.CommitChanges()
}

For adding bulk users from text file use the below script, it is very easy to use and this guy has written pretty neat

https://gallery.technet.microsoft.com/Add-Bulk-Users-to-6f3014b2