Mail Express Pro is a useful application that is designed to help you send e-mails to recipients by yourself. It has a high-performance Internal Delivery Engine that support group-mailing. You can also add all your SMTP servers in it, and Mail Express Pro will work as a SMTP router with rule support. Multi-thread technology is used in it, so you can set up to 100 threads to send e-mails. Mail Express Pro provide detailed logs and delivery-progress view to view your e-mail delivery status. If some e-mails are sent failed, Mail Express Pro will move them to 'failed' folder and send you a notify e-mail (always because of incorrect e-mail address of recipient), then you can correct it and resend it, all operations are in Mail Express Pro. But all what you need to do is to change the SMTP server setting of your mail software to 'localhost'.