Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!math.fu-berlin.de!fauern!opal!gmdtub!simon!simon From: simon@opal.CS.TU-Berlin.DE (Simon Leinen) Newsgroups: comp.mail.sendmail Subject: Re: Using numerical addresses Message-ID: Date: 8 Apr 91 17:01:54 GMT References: Sender: news@bigfoot.first.gmd.de Reply-To: simon@opal.CS.TU-Berlin.DE Organization: GMD-FIRST, Berlin Lines: 30 In-reply-to: srf@claudius.juliet.ll.mit.edu's message of 5 Apr 91 14:56:53 GMT >>>>> On 5 Apr 91 14:56:53 GMT, srf@claudius.juliet.ll.mit.edu ( Steve >>>>> Feinstein) said: Steve> Is it possible to send mail using numerical addresses instead Steve> of domain names? From RFC 821 (Simple Mail Transfer Protocol): ... One form is a decimal integer prefixed by a pound sign, "#", which indicates the number is the address of the host. Another form is four small decimal integers separated by dots and enclosed by brackets, e.g., "[123.255.37.2]", which indicates a 32-bit ARPA Internet Address in four 8-bit fields. So you can probably use addresses of the form simon@[192.35.149.176] (works for me). Steve> Our yp hosts database is far from complete and rather than Steve> constantly asking our sys admin to add names to it, I'd like to Steve> be able to send mail based on the numerical address. The correct solution to your problems would be to use the Domain Name System. This is something like a huge distributed database that transparently maps (among other things) qualified hostnames to IP-addresses by querying different name servers on the Internet. -- Simon. Internet: simon@[192.35.149.176] simon@Opal.CS.TU-Berlin.DE