The Postfix Home Page
All programmers are optimists -- Frederick P. Brooks, Jr.
First of all, thank you for your interest in the Postfix project.
Postfix attempts to be fast, easy to administer, and secure. The outside has a definite Sendmail-ish flavor, but the inside is completely different.
Postfix does not call gethostbyname() since 2005. There is no Postfix code that invokes this function unless Postfix is specifically built for operating systems from more than 10 years ago (this requires the compile-time option -DNO_IPV6). Even then, Postfix calls gethostbyname() only after it has verified with inet_pton() that the argument is not an IP address.
About this website
This website has information about the Postfix source code distribution. Built from source code, Postfix can run on UNIX-like systems including AIX, BSD, HP-UX, Linux, MacOS X, Solaris, and more.
Postfix is also distributed as ready-to-run code by operating system vendors, appliance vendors, and other providers. Their versions may have small differences with the software that is described on this website.