A friend* wonders about the SMTP treatment of addresses in TLDs. Historically there have been a smattering of such addresses, most famously n...@ai, and there are 21 TLDs with MX records, but spot checking shows that most appear to be config mistakes, with the MTAs not actually accepting mail to postmas...@tld.
If ICANN does what they claim they're going to do and starts selling thousands of new TLDs, we're likely to see a lot more dotless addresses. b...@aol, anyone? As best I understand it, the prose description of addresses in 2821 allowed TLDs in addresses, but the ABNF didn't. In 5321 the ABNF changed to match the prose. Although the DNS allows you to put a dot at the end of a domain name to make it clear that it's an absolute address, SMTP has never allowed that. My impression is that in the real world, mail addressed to postmas...@va is far more likely to be rewritten to [email protected] than delivered to the Vatican (which, as it happens, will accept it.) Mail addressed to postma...@va. with a dot isn't valid under 821, 2821, or 5321, so some MTAs accept it, some reject it. Is the current situation with TLDs deliberate, or was the change in 5321 just aesthetic tidying up? Is there any reason not to permit a trailing dot in 5321-bis to bring it in line with DNS rules? Regards, John Levine, [email protected], Primary Perpetrator of "The Internet for Dummies", Information Superhighwayman wanna-be, http://www.johnlevine.com, ex-Mayor "More Wiener schnitzel, please", said Tom, revealingly. * - no, really
