Henrik K a écrit : > On Sun, Jan 18, 2009 at 03:45:25PM +0100, mouss wrote: >> Henrik K a écrit : >[snip] >>> Less info only if you are running a sad MTA, that doesn't properly resolve. >> not completely true. >> >> $ host 220.174.1.163 >> 163.1.174.220.in-addr.arpa domain name pointer >> 163.1.174.220.broad.hk.hi.dynamic.163data.com.cn. >> $ host 163.1.174.220.broad.hk.hi.dynamic.163data.com.cn >> Host 163.1.174.220.broad.hk.hi.dynamic.163data.com.cn not found: 3(NXDOMAIN) >> >> if you get a message from this IP, postfix will set the name to >> "unknown". so you won't detect that the PTR is dynamic. >> >> and "unknown" is also used if there is a dns failure, or if the PTR >> doesn't "confirm" (ip -> ptr -> different IP). so you can't treat all >> "unknown" similarly. >> >> I know you can block the IP in postfix (I block the whole >> dynamic.163data.com.cn), but this is just an example (I'm too lazy to >> look for a better one), and I hope you see my point. > > Well, for what it matters, unknown is fine by mine. I greylist all of them. > I block unknowns that are in any BLs. I don't directly block hostnames with > dynamic content (only known bad isps), but I do block dynamic helos. I don't > see any problems on what you said. >
I only meant that you can have "less infos" even with a not so "sad MTA". This may not be a problem for you, but other people may want to score if PTR is dynamic (even if helo is not).
