QK SMTP Server is a powerful but easy-to-use smtp server software. It sends mails from local host to the recipients' mailboxes directly at an amazingly high speed, you will get a feedback instantly. It works well with most mail clients, such as Outlook Express, Eudora, IncrediMail, the Bat!, Mutt, KMail, Pegasus, DevMail, Mail Bomber, Delta Mail, Foxmail;It can also work with most bulk mail software to improve efficiency.