Postfix Origins and Philosophy
Postfix was written by Wietse Venema, who is widely known for his security tools and papers. It was made available as open source software in December 1998. IBM Research sponsored the initial release and has continued to support its ongoing development. (IBM calls the package Secure Mailer.) There were certain goals from the beginning that drove the design and development of Postfix:
- Reliability
Postfix shows its real value when operating under stressful conditions. Even within simple environments, software can encounter unexpected conditions. For example, many software systems behave unpredictably when they run out of memory or disk space. Postfix detects such conditions, and rather than make the problem worse, gives the system a chance to recover. Regardless of hazards thrown its way, Postfix takes every precaution to function in a stable and reliable way.
- Security
Postfix assumes it is running in a hostile environment. It employs multiple layers of defense to protect against attackers. The security concept of least privilege is employed throughout the Postfix system, so that each process, which can be run within an isolated compartment, runs with the lowest set of privileges it needs. Processes running with higher privileges never trust the unprivileged processes. Likewise, unneeded modules can be disabled, enhancing security and simplifying an installation.
- Performance
Postfix was written with performance in mind and, in fact, takes steps to ensure that ...