When I used combination of cmdlet create a bulk mailbox and modify attribute e.g. company, title and etc. Sometime, it was failed to modify certain new user with error user not found. I find this link http://unlockpowershell.wordpress.com/2010/01/08/powershell-dealing-with-active-directory-latency/ which i believe the root cause. I tried create cmdlet with combination of -DomainController, it work foreach ($user in $users) { New-Mailbox -Name $user.name -FirstName $user.firstname -LastName $user.lastname -Alias $user.alias -UserPrincipalName ($user.alias +'@contoso') -Database $user.database -OrganizationalUnit $user.org -Password ( ConvertTo-SecureString sst2011 -AsPlainText -Force) -ResetPasswordOnNextLogon:$false -DomainController dc03.contoso.com Set-User -Identity $user.alias -Company $user.Comp -Title $user.title -Department $user.department -Manager $user.manager -Office $user.office -DomainController dc03.contoso.com Add-DistributionGroupMember $user.groups -Member $user.alias -DomainController DC03.contoso.com } However, i try to use do...while but I'm stuck please help. $users = Import-Csv c:\ps\CreateMailbox.csv foreach ($user in $users) { New-Mailbox -Name $user.name -FirstName $user.firstname -LastName $user.lastname -Alias $user.alias -UserPrincipalName ($user.alias +'@contoso') -Database $user.database -OrganizationalUnit $user.org -Password ( ConvertTo-SecureString sst2011 -AsPlainText -Force) -ResetPasswordOnNextLogon:$false do { Get-Mailbox -Identity $user.alias -ErrorAction SilentlyContinue } While ($users.alias -eq $null) Set-User -Identity $user.alias -Company $user.Comp -Title $user.title -Department $user.department -Manager $user.manager -Office $user.office Add-DistributionGroupMember $user.groups -Member $user.alias }

Try (untested) do { $mailbox = Get-Mailbox -Identity $user.alias -ErrorAction SilentlyContinue } While ($mailbox -eq $null) Karl http://unlockpowershell.wordpress.com -join("6B61726C6D69747363686B65406D742E6E6574"-split"(?<=\G.{2})",19|%{[char][int]"0x$_"})