A method, system and computer program for operating an application server using email messages uses the address format of the email address of an incoming email message to invoke an application to process the content of an incoming message. Each application available on the server defines acceptable address formats of the email addresses of messages that it will accept for processing. An application may generate a reply to an incoming email message, or may generate an event, to advance processing of a task. The application server may also determine a recipient email address of an actual recipient of the incoming e-mail, and transmit the incoming e-mail message to the recipient email address. In this case, the application server functions by interposing itself in the email channel between two recipients.