Xref: utzoo comp.mail.uucp:4039 news.sysadmin:2835 Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!snorkelwacker!mit-eddie!bu.edu!bu-pub.bu.edu!ckd From: ckd@bu-pub.bu.edu (Christopher Davis) Newsgroups: comp.mail.uucp,news.sysadmin Subject: Re: Regarding earlier post on domains. Message-ID: Date: 6 Mar 90 11:46:03 GMT References: <75@dynasys.UUCP> Sender: news@bu.edu.bu.edu Reply-To: ckd@bu-pub.bu.edu (Christopher Davis) Followup-To: comp.mail.uucp Organization: Boston University School of Management Lines: 60 In-reply-to: jessea@dynasys.UUCP's message of 6 Mar 90 02:01:11 GMT >>>>> On 6 Mar 90 02:01:11 GMT, jessea@dynasys.UUCP (Jesse W. Asher) said: > [...] The more I find out about this, the less convinced I am of the > greatness of domains. Question: Why in the world would I want to have > mail sent to another site just so that site could send it to me? > If, for example, my domain is "dynasys.com", what is the advantage of > having my mail sent to the entity that takes care of the "com" domain > only to then be sent to me? Especially when we have smart mailers that > will route the stuff directly to me. After reading the RFC and asking > all these questions, domains do not seem to be the great thing that many > are making them out to be. Comments? This seems to be a misinterpretation of how the DNS MX record is handled. The advantage here is that sites using DNS (we will, for the moment, ignore UUCP pathalias/comp.mail.maps style routing) do a lookup, get an MX, then send the mail *over the Internet* to that MX. Example: Bill Well's machine, twwells.com: Script started on Tue Mar 6 06:38:59 1990 6:39am ckd@bass : ~ % nslookup Default Server: BU-PUB.BU.EDU Address: 128.197.21.21 [...] > twwells.com Server: uunet.uu.net Address: 192.48.96.2 twwells.com origin = uunet.UU.NET mail addr = postmaster.uunet.UU.NET serial=900228, refresh=432000, retry=3600, expire=864000, min=172800 twwells.com server name = uunet.UU.NET twwells.com server name = seismo.CSS.GOV twwells.com preference = 200, mail exchanger = uunet.uu.net uunet.UU.NET inet address = 192.48.96.2 uunet.UU.NET inet address = 137.39.1.2 seismo.CSS.GOV inet address = 192.12.141.25 [...] script done on Tue Mar 6 06:39:51 1990 The magic part is the line reading: twwells.com preference = 200, mail exchanger = uunet.uu.net which means that my mailer will send mail for user@twwells.com to uunet.uu.net through the Internet, and uunet can then arrange to get it to you. Otherwise, I might have to use twwells!user@uunet.uu.net, or user%twwells.uucp@uunet.uu.net, or other strange and arcane mutterings, just to get mail through to you. Mail does not go to "the entity that takes care of the 'com' domain" (namely nic.ddn.mil)--they just register your domain so nobody else gets it. (Imagine if Boston U, Brown U, and Bucknell U all used "bu.edu"...) Naturally, NONE of this applies outside the DNS (in particular, none of this applies to sites using comp.mail.maps for routing). -- Christopher Davis, BU SMG '90 "Basic upshot - get your science straight, or start getting used to the taste of your Nikes." --Siobahn Morgan, thebang@blake.acs.washington.edu