JKL put forth on 2/2/2011 12:23 PM: > > On 02/02/2011 06:17 PM, Victor Duchovni wrote: >> On Wed, Feb 02, 2011 at 05:30:52PM +0100, J4K wrote: >> >>> The smtpd has a 'sleep 3' at the start of it. Might this have been the >>> cause? If so, then it served the purpose. >>> >>> smtpd_recipient_restrictions = sleep 3, >>> permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination, >>> reject_non_fqdn_sender, reject_rbl_client >>> hostkarma.junkemailfilter.com=127.0.0.2, reject_rbl_client zen.spamhaus.org >> Unconditional "sleep <n>" applied even to servers that repeatedly pass >> the test damages email infrastructure (by forcing legitimate servers >> to expand substantially more resources, and delaying their email to >> other destinations). Please don't do this. Consider upgrading to Postfix >> 2.8 and deploying postscreen(8) which remembers which servers pass the >> test. >> > Valid point. I have removed the sleep condition and shall see how much > extra spam is received. I shall upgrade to 2.8 and postscreen when its > available as a Debian package.
In the mean time, maybe give this a go. 1600+ expressions matching rDNS patterns of many millions of broadband IPs worldwide that shouldn't be sending direct SMTP. Catches quite a bit that PBL/CBL/SORBS-DYNA/etc don't and with less delay, reduced load on dnsbl servers and your own network. Potential FPs will be SOHO and "Linux weenie" MTAs on consumer IPs. Usage instructions are comments at the top of the file. Insert the restriction above/before any greylisting daemons in main.cf, obviously. Some on this list and many on the Dovecot list can testify to its effectiveness. http://www.hardwarefreak.com/fqrdns.pcre Of note, I also run Debian Lenny, and the backports Postfix 2.7.1, and have been using exclusively Debian on my servers since ~2001. -- Stan
