Octeth

1. Since Qmail was developed by Dan Bernstain (author) in 1998-99 there has not been an official update. He claims to be working on a new release since 10 Apr 2001. So we are not sure if we should ever expect another official release. Right now you have bunch of groups and open source coders releasing patches left and right, which sometimes conflict with each other. The original qmail build therefore really does not have a lot of features although like I mentioned you can find patches galore on the web. With the requirement to negotiate the chaos of qmail patch sets, you need to have a lot of dedication to ensure your configuration is a good one. You might find qmail works for small sites without much configuration, but that will entirely depend on how your particular email workload is skewed. With that said, Qmail is officially UNMAINTAINED is the bottom line!
2. Installation is somewhat difficult for qmail compared to postfix. This really is not a big deal, after-all you are looking at performance once installed, not the actual process of installing it. All the same, there are not a whole lot of binary rpm packages available (although some do exist), which require compiling from source for qmail.
3. The documentation on qmail is sometimes very confusing when compared to postfix.
4. Postfix delivers such great flexibility and ease of administration despite meeting strict security goals. Qmail is also regarded as highly secure, however it does not, by design policy, give the administrator anything like the flexibility of Postfix.
5. If you are looking for less hassle after the initial setup of your MTA, then you better take a good look at Postfix. In our experience qmail is a real hassle when you start to need to change configurations for heavy mail loads. It is not that qmail can not handle heavy mail loads, but rather it being a real headache to make configuration changes when required to deal with such tasks.
6. Postfix has been measured by many as being extremely fast and we would tend to agree. I have found it very efficient. Qmail is comparatively similar in this regard however. Postfix and qmail also seem to use about the same amount of memory but by deliberate design qmail uses a bit more bandwidth than Postfix, but not enough to really factor into the equation of choosing between the two.
7. Security: Both MTA’s are pretty secure, each having a few security flaws, but not near as many as all the other MTA’s available. qmail is secure but very old and cranky; Postfix is secure and more modern. Again goes back to author support.
8. Performance: The performance of both Postfix and Qmail are very high, and if you have the right hardware either of these are suitable for large mailing lists if configuration is put into place. We have tested both MTA’s with lists in the hundreds of thousands in conjunction with Oempro, and after the initial configuration changes, both worked very well.
9. If you are serious about performance and emailing on a large scale (hundreds of thousands of subscribers, even millions) then do yourself a favor and do not install a Web Hosting Control Panel, nor a pre-packaged MTA. Instead build your server based on the fact that it will be used for mass mailing to of course your opt-in subscribers!

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16th Aug 2007, Posted by Cem Hurturk under Newsletter Sending and Deliverability