+1 Dick
On Tue, 2004-03-30 at 21:03, Davide Libenzi wrote: > On Tue, 30 Mar 2004, Tracy wrote: > > > FCrDNS: Take the connecting IP address, retrieve all PTR records (hopefully > > only one, but possible to get more). Then take the PTR record(s) and do A > > lookup on it. Compare the connecting IP address to the A records returned - > > if no match, either the DNS for the connecting IP has been > > misconfigured/corrupted, or it's being forged by a spammer. (Of course, > > this assumes that RDNS is in place for all connecting IP addresses - a > > policy I have implemented for my server anyway.) > > > > RCfDNS: Take the HELO/HELO name, retrieve all A records. Starting with the > > first returned A record, do PTR lookup. If HELO/EHLO matched PTR found for > > any A record, assume valid, otherwise reject as misconfigured/corrupt DNS > > or forgery. > > > > The RCfDNS is going to be expensive, due to the possible number of lookups > > and the string comparisons,so it may not be worth the expense. However the > > FCrDNS I definitely want to implement. > > > > I don't know if you would be interested in this kind of code or not for > > inclusion in a future version - if so (and you can stand my poor coding > > skills :) I'd be happy to share once I have something working... > > Nope. But I was thinking that XMail could have a special filter call right > before sending the response to the DATA command. A file with all the info > (IPs, sender, recipients, etc..) will be passed to the filter, that in > turn can reject by returning certain error codes. So this stuff can be > done with filters. How do you like it? > > > > - Davide > > > - > To unsubscribe from this list: send the line "unsubscribe xmail" in > the body of a message to [EMAIL PROTECTED] > For general help: send the line "help" in the body of a message to > [EMAIL PROTECTED] > - To unsubscribe from this list: send the line "unsubscribe xmail" in the body of a message to [EMAIL PROTECTED] For general help: send the line "help" in the body of a message to [EMAIL PROTECTED]
