Why Bother Writing Postfix?

As soon as word got out that I was working on a mailer, people asked me if I hadn't heard of qmail.

Well, that question needs no answer anymore. If qmail was an acceptable solution for me, I would use it myself, instead of writing my own mailer system.

With all due respect, I do not consider qmail-1.01 a general-purpose MTA. For starters, it is severely lacking support for non-internet addresses - qmail rejects the entire message when it has a problem parsing a sender or recipient address. It also lacks support for address rewriting (From: To: Cc:) of messages from the network - the qmail FAQ document illustrates this point very well. In a perfect world, every program generates correct SMTP addresses. That may be so, but the real world is not perfect.

But the most important consideration is compatibility. When I run a sendmail-based network with hundreds of systems and with thousands of users, I cannot expect all those users to suddenly change the way they use the email system. If I am going to replace sendmail by something else, it better be compatible. Replacement is not an option unless the new system supports NIS aliases, /etc/aliases, and ~/.forward files, shell commands and all that.

In all fairness, it must be said that the qmail program has evolved since I wrote the initial version of this text. The qmail author has provided significant improvements in sendmail compatibility.

Some people have taken offense to my claims about shortcomings in qmail. I would like to remind those who took offense that there are more important things in life than computers and mailers. For enlightment, see the Linux advocacy web page. Instead of Linux, pretend it is about Postfix or qmail, or whatever turns you on.