Mail Express Pro is designed to help you send e-mails to recipients by yourself. It has an Internal Delivery Engine that supports group mailing. You can 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 emails.

Mail Express Pro makes detailed logs and delivery-progress view to view your e-mail delivery status.If some emails are sent failed, Mail Express Pro will move them to 'failed' folder and send you a notify email, then you can correct it and resend it. But all what you need to do is to change the SMTP server setting of your mail software to 'localhost'.