Connect-ExchangeOnline

$since = (Get-Date).AddDays(-30)

$devices = Get-MobileDevice -ResultSize Unlimited |
Where-Object {
    ($_.ClientType -eq 'EAS' -or $_.ClientType -match 'ActiveSync') -and
    $_.ClientVersion -and
    ([version]$_.ClientVersion -lt [version]'16.1')
}

$report = foreach ($d in $devices) {
    $s = Get-MobileDeviceStatistics -Identity $d.Identity -ErrorAction SilentlyContinue
    if ($s -and $s.LastSuccessSync -and $s.LastSuccessSync -ge $since) {
        [pscustomobject]@{
            UserDisplayName   = $d.UserDisplayName
            Mailbox           = $d.UserPrincipalName
            DeviceId          = $d.DeviceId
            DeviceModel       = $s.DeviceModel
            DeviceOS          = $s.DeviceOS
            ClientType        = $d.ClientType
            ClientVersion     = $d.ClientVersion
            LastSuccessSync   = $s.LastSuccessSync
            FirstSyncTime     = $s.FirstSyncTime
            Status            = $s.Status
        }
    }
}

$report | Sort-Object UserDisplayName | Format-Table -AutoSize
$report | Export-Csv .\ActiveSync_Last30Days.csv -NoTypeInformation -Encoding UTF8