Re: Which mail server?
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
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
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?