Shane Chrisp wrote:
On Fri, 2006-02-24 at 11:00 +0000, Cameron L. Spitzer wrote:Is qmail is good enough or do I have to choose postfix or exim? Which one and why?Qmail's got two problems that were enough for me to replace it. 1. It doesn't know how to reject anything in the SMTP cycle. It swallows everything and then barfs up the crap. Generates a lot of backscatter. So much that you can get blocked by AOL if some spammer spoofs them a lot.This is not quite true. There is patches and helper programs which do reject at the smtp level. Using ucspi-tcp allows the blocking of messages at the smtp conversation, and then combined with simscan you can also do filtering of spam and viruses and drop them at the smtp conversation level as well.
Yes ! Please see http://qmail-spp.sourceforge.net/plugins/ All those plugins work at the SMTP level, before having traffic.
Still in qmail-spp, the plugin "trapit" can be used for that kind of trouble. It adds a slow down between recipients, the more you add recipent, the more delay it adds, making it almost unusable the way you described (with 500 recipients). Most tool would just timeout and fail.2. It doesn't know how to bunch together multiple recipients of the same message in the same domain. So if you have 500 Yahoo subscribers on a mailing list, it takes 500 separate processes and SMTP transactions to deliver them. Yahoo will block you for that. Postfix will collect them together and do one SMTP transaction.Though im not 100% certain on this one, I am fairly certain there is a patch for this as well.
To me, the biggest problem with Qmail is more delayed bounce. Normally it doesn't happen because of the protections you have (SPF, RBL, trapit, etc...), but if for one reason it does, then your queue can be filled very fast. Does some of you know how to totally disable delayed bounce?
Thomas