1. There is only one ptr record per IP. 2. Yes. 3. No. Validation is pretty much impossible. Most of the time, validation consists of it is $ptr ne ''. 4. I don't know what end goal you are trying to achieve but using reverse records for any type of sercurity or blocking has pretty high false positive rates. ISPs in my experience don't even really care about setting reverse DNS up.
Regards, KAM > 1. Is it okay to use the first (and only the first) PTR record? > 2. Is it okay to use the (default) recursive search? > 3. Is it okay to use the first "A" record to validate > the name returned by rDNS? > 4. Does this seem like a reasonable way to validate a HELO IP > address and convert it into a useable HELO address? _______________________________________________ NOTE: If there is a disclaimer or other legal boilerplate in the above message, it is NULL AND VOID. You may ignore it. Visit http://www.mimedefang.org and http://www.roaringpenguin.com MIMEDefang mailing list [email protected] http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
