$result_file = New-Item -ItemType file -Path result.txt -Force
$import_file = Import-Csv -Path import_mailbox.txt 
Add-Content -Path $result_file -Value "displayname,alias,database"
Foreach ( $line in $import_file )
{
$user = Get-Mailbox -Identity $line.Alias
 
 if ( $user.database -match "mdb1" -and $user.OrganizationalUnit -match "OU_001" )
{
Add-Content -Path $result_file -Value "$($user.displayname),$($user.alias),$($user.database)"
}
 else {}
}