PHP SMTP Server is a SMTP server program that can be used as a local SMTP server or as a corporate high-performance SMTP server. It can be used along with virtually any mailer or email program including Microsoft Outlook, Outlook Express, Eudora, Netscape and The Bat, and it is ideal for laptop PC users who travel a lot and have to use different Internet Service Providers (ISP) on the run. You can use it instead of your ISP's SMTP server to increase your email security and privacy due to your email messages will be delivered directly to the mailboxes of your recipients. The email program you already use for sending messages can be connected to the server in a very easy way - just by using the word "localhost" instead of your current SMTP host. Having done so, you can send messages in a usual manner.