Managing mail with MMDF

Specifying MMDF authorizations

Control the flow of mail through your host using MMDF authorizations. You can authorize mail to be sent from your host on specific channels, based on the sending or receiving host, the user who originates the mail, or both. You can also authorize mail routed through your domain.

Host-based authorizations: This form of authorization control (see ``Specifying host-based authorization'' for instructions) is often used to ensure that hosts that are not part of the site's private network do not use that network to send mail to other parts of the world. For example, you can use host-based authorization to allow mail to enter your domain, but restrict the mail passing through it.
User-based authorization: Control the flow of mail both to and from your host and network using this form of authorization control (see ``Specifying user-based authorization'' for instructions). For example, if your site is on the Internet, you might want to allow your employees (but no one else) to send mail from their home machines through your system to the Internet. In this case, you would want to set up MMDF to authorize mail from employee users to pass through your machine, but prevent mail from other users from passing through.
Routing-based authorization: Keep mail that enters your domain from leaving your domain using this form of authorization control (see ``Setting routing-based authorization'' for instructions). Users in your domain can send mail to people both inside and outside the domain, but users outside the domain cannot route mail through your domain to another destination. For example, if your domain includes machines in different cities with links to different outside computers, people from outside the domain might use these links to send mail from one city to another, through your domain. In this case, you can set up MMDF authorization to prevent people from using your system to transfer mail.