Richard Hector wrote: > This is an OpenPGP/MIME signed message (RFC 4880 and 3156) > --74MY4YRdzqYrpY64nFoecBsxLWqTbYeLg > Content-Type: multipart/mixed; boundary="W7QULzTEwHyPVYL9CjAwUAkHYtJwwuUvr"; > protected-headers="v1" > From: Richard Hector <rich...@walnut.gen.nz> > To: debian-user@lists.debian.org > Message-ID: <3d20dce8-38ee-dbac-e8a5-c13b79f84...@walnut.gen.nz> > Subject: Re: Federated, decentralised communication on the internet > References: <20180215143806.vii235crrmr4t...@eeg.ccf.org> > <slrnp8bcsg.ask....@xps-linux.djph.net> > <1519043283.383068.1275644336.01c71...@webmail.messagingengine.com> > <20180219162356.GA4712@alum> > <19022018180243.2ced26b8f...@desktop.copernicus.org.uk> > <20180222175818.GA12408@alum> > <23022018142458.08644849f...@desktop.copernicus.org.uk> > <20180320220747.GA14927@alum> <85muz2z7iw.fsf...@benfinney.id.au> > <20180321195347.GD7863@alum> <20180321202144.3oxfe5puynsf5...@eeg.ccf.org> > In-Reply-To: <20180321202144.3oxfe5puynsf5...@eeg.ccf.org> > > --W7QULzTEwHyPVYL9CjAwUAkHYtJwwuUvr > Content-Type: text/plain; charset=utf-8 > Content-Language: en-US > Content-Transfer-Encoding: quoted-printable > > On 22/03/18 09:21, Greg Wooledge wrote: >> One heuristic that is commonly used is to reject all messages where >> the HELO doesn't even syntactically qualify as a valid FQDN -- in other= > >> words, has no dot in it. > > I often see this alluded to, but struggle to find evidence - why > shouldn't there be a postmaster@com, for example? Or perhaps cic@mil? > > Is there any reason you can't have an A, MX or any other record on a > TLD? Or even the root, though I concede that abuse@. would be easier to > understand than just abuse@ [attempts to end sentence without a dot]
It is my understanding that the TLDs are not themselves valid domains. That is, a valid domain is by definition "domain.tld". I could be entirely wrong though. -- |_|O|_| Registered Linux user #585947 |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281
