On Fri, Jun 21, 2002 at 05:16:00PM -0500, Lindsay Haisley wrote: > > It doesn't appear that from a functional point of view it should matter that > an MX record uses a number rather than a name, although I may not understand
Yes, it does. Because MX's point to hostnames, you are supposed to take the value of the MX record, and use it to query for A records. Hostnames and IP addresses are stored differently, in DNS. Hostnames are stored as, essentially, text strings, while IP addresses are stored as, obviously, 32-bit words. So, the result of the MX record is then resolved as a query for A record. Now, obviously there will not be a host named, say, "192.168.128.3" on the Internet; in fact, "3" is obviously not a valid top-level domain. This particular code fragment heuristicaly recognizes hostnames that look like IP addresses, and doesn't even bother with an A lookup, rejecting the MX record as invalid, and with a pointer to the relevant record. > Any insight would be appreciated. I have a customer who is unhappy because > one of his his correspondants can't reach him and the ISP with misconfigured > DNS is both unresponsive and probably the only ISP available for many people > in the community in which it's located. Accomodating incompetence only breeds more incompetence. That's not a good thing. -- Sam ------------------------------------------------------- Sponsored by: ThinkGeek at http://www.ThinkGeek.com/ _______________________________________________ courier-users mailing list [EMAIL PROTECTED] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
