Function New-O365ExchangeSession(){

    param(
    [parameter(mandatory=$true)]
    $Credentials)

    #close any old remote session
    Get-PSSession | Remove-PSSession -Confirm:$false
    [System.GC]::Collect()

    #start a new office 365 remote session
    $365session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $Credentials -Authentication Basic -AllowRedirection
    Import-PSSession $365session -AllowClobber
}

$startd = Get-Date

## Get Password
## Removed credential retrieval for pastebin

## Grab the middle school students and list of classes students take
$schools = Import-Csv C:\scripts\Dirsync\SDS\middleschools.csv
$students = Import-Csv C:\scripts\Dirsync\SDS\student.csv | Where-Object { $schools.sisid -contains $_."school SIS ID" }
$stuenroll = Import-Csv C:\scripts\Dirsync\SDS\StudentEnrollment.csv

## Connect to Exchange Online
New-O365ExchangeSession -Credentials $cred

## Get all O365 groups for MS Classroom
$Groups = Get-UnifiedGroup -ResultSize Unlimited -Filter {(name -like "Section_*") -and (alias -notlike "SDSRetired*")}

## Get count and start breaking up the list to keep O365 session from timing out
$rescount = $students.Count
$offset = 0
$pagesize = 200

Do {

    $students | Select-Object -Skip $offset -First $pagesize | ForEach-Object {
        ## Set variable for ease of use
        $s = $_

        ## Get Mailbox for each entry
        $GMBX = Get-Mailbox $s.username
        Write-Host $s.username

        ## Query for Custom Attribute 2
        $restricted = ($GMBX).customattribute2
        $restricted

        ## If CA2 is set to "Restricted" we will add group to the acceptance restrictions on the mailbox
        If ($restricted -eq "Restricted") {
            ## Get the classes the student is enrolled in
            $classes = $stuenroll | ? { $_."sis id" -contains $s."sis id"}

            foreach ($c in $classes){
                ## Find the correct O365 group for that class, set it to the student restrictions if not already set
                $assign = $groups | ? {$_.name.replace("Section_","") -like "*$($c.'Section SIS ID')*"}

                ## Set $accept as an explicit string of AcceptMessagesOnlyFromSendersOrMembers to fix if statement
                [string]$accept = $gmbx.AcceptMessagesOnlyFromSendersOrMembers
                if ($accept -notlike "*$($c.'Section SIS ID')*"){
                    Set-Mailbox $s.Username -AcceptMessagesOnlyFromSendersorMembers @{add= $assign.Name}
                    Write-Host "set mailbox on " $s.username
                    $assign.name
                }
            }
        }
    }
    ##Recreate the session to keep it from timing out
    New-O365ExchangeSession -Credentials $cred

    ## Set offset to restart at next 200
    $Offset += $PageSize
}
While ($offset -lt $rescount)

$startd
get-date