Need to create new users in Office 365 with custom attributes from a csv file

Question

I am exporting users from an active directory environment and then deleting them from AD. They are Alumni and will no longer be in AD.
I have a csv file with the following fields that I need to use to create new Alumni email boxes in Office 365 for. I need the CustomAttributes because my Dynamic Distribution Groups use them. I am fairly new to PowerShell and have been unable to get this
to work. I suspect I may have to split it into two parts, but am not sure how to proceed. Any assistance would be appreciated. I was directed here from the Office 365 community.
Import-Csv -Path c:\CSVfiles\CreateAlumni.csv | ForEach-Object {
   New-MsolUser -FirstName $_.FirstName -LastName $_.LastName
   -UserPrincipalName $_.UserPrincipalName
   -DisplayName "$($_.FirstName) $($_.LastName)"
   -Password $_.Password
   -CustomAttribute1 $_.CustomAttribute1
   -CustomAttribute3 $_.CustomAttribute3
   -CustomAttribute10 $_.CustomAttribute10
   -CustomAttribute11 $_.CustomAttribute11
   -CustomAttribute12 $_.CustomAttribute12
   -LicenseAssignment 'domaincom:EXCHANGESTANDARD_ALUMNI'
   -UsageLocation US

Answer 1

Ok, it wasn't stopping after 2 iterations. What I was seeing was 2 failures. The first was the Get-Mailbox command and the second was when it tried to assign attributes. For some reason it is not looping when it fails. It just goes on and tries to assign
the Custom Attributes. I added writes in to tell me what was happening.
### Check if mailbox is provisioned yet
Write-Host "Checking if mailbox is provisioned yet..." -foregroundcolor yellow
$found = $false
$count = 0
Do {
try {
Get-Mailbox -Identity $_.UserName -ErrorAction Stop
$found = $true
Write-Output 'Mailbox found. Details:'
Get-Mailbox -Identity $_.UserName
} catch {
Write-Output 'Sleeping'
$count++
Start-Sleep -Seconds 5
If ($count -ge 12) {
Write-Output 'Mailbox not found. Quitting.'
$found = $true
} Until ($found)
Write-Host "Adding Custom Attributes to User" -foregroundcolor yellow
Set-Mailbox -Identity $_.UserName -CustomAttribute1 $_.CustomAttribute1 -CustomAttribute3 $_.CustomAttribute3 -CustomAttribute10 $_.CustomAttribute10 -CustomAttribute11 $_.CustomAttribute11 -CustomAttribute12 $_.CustomAttribute12
Write-Output "User has been Provisioned in Office 365!" -foregroundcolor yellow
Checking if mailbox is provisioned yet...
The operation couldn't be performed because object 'Joe.Cool2003' couldn't be found on 'CO1PR07A002DC01.NAMPR07A002.prod.outlook.com'.
    + CategoryInfo         
: NotSpecified: (:) [Get-Mailbox], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : [Server=CO1PR07MB125,RequestId=e1aabda1-01e4-4f68-984e-e20be0975242,TimeStamp=5/22/2014 4:23:59 AM] [FailureCategory=Cmdlet-ManagementObj
   ectNotFoundException] 2788FB48,Microsoft.Exchange.Management.RecipientTasks.GetMailbox
    + PSComputerName        : pod51038psh.outlook.com
Mailbox found. Details:
The operation couldn't be performed because object 'Joe.Cool2003' couldn't be found on 'CO1PR07A002DC01.NAMPR07A002.prod.outlook.com'.
    + CategoryInfo         
: NotSpecified: (:) [Get-Mailbox], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : [Server=CO1PR07MB125,RequestId=16a8a2bc-333a-455c-8504-e0b99c44c334,TimeStamp=5/22/2014 4:24:00 AM] [FailureCategory=Cmdlet-ManagementObj
   ectNotFoundException] 2788FB48,Microsoft.Exchange.Management.RecipientTasks.GetMailbox
    + PSComputerName       
: pod51038psh.outlook.com
Adding Custom Attributes to User
The operation couldn't be performed because object 'Joe.Cool2003' couldn't be found on 'CO1PR07A002DC01.NAMPR07A002.prod.outlook.com'.
    + CategoryInfo         
: NotSpecified: (:) [Set-Mailbox], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : [Server=CO1PR07MB125,RequestId=8319d220-b9dd-492f-8182-5083cf56e58b,TimeStamp=5/22/2014 4:24:00 AM] [FailureCategory=Cmdlet-ManagementObj
   ectNotFoundException] C7844A24,Microsoft.Exchange.Management.RecipientTasks.SetMailbox
    + PSComputerName       
: pod51038psh.outlook.com
User has been Provisioned in Office 365!
Of course the user has been provisioned, but the CustomAttributes have not been assigned. :(