unqualified domains, was ICANN to allow commercial gTLDs

Tony Finch dot at dotat.at
Mon Jun 20 17:28:40 UTC 2011

On 20 Jun 2011, at 02:24, Paul Vixie <vixie at isc.org> wrote:
> furthermore, the internet has more in it than just the web, and i know that
> "foo at sony." will not have its RHS ("sony.") treated as a hierarchical name.

Trailing dots are not permitted on mail domains.

There has been an ongoing argument about the interaction between unqualified domains and TLDs in mail domains. RFC 2821 said single-label mail domains were syntax errors, but this was probably an editorial mistake and RFC 5321 permits them. It's probably safest to assume that a single-label mail domain is a local unqualified domain which will have its qualifying labels appended by the message submission server, and in other contexts all bets are off.

f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/

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