On Wed, 30 Oct 2013 20:13:40 +0100 Matus UHLAR - fantomas wrote: > >On Wed, 30 Oct 2013 11:44:19 -0400 > >David F. Skoll wrote: > > > >> On Wed, 30 Oct 2013 11:06:35 -0500 > >> Adam Moffett <adamli...@plexicomm.net> wrote: > >> > >> > I'm reasonably sure that user@ip makes a valid address, but even > >> > if it is I don't think I've ever observed it anywhere. > >> > >> My reading of RFC5321 seems to indicate that "user@1.2.3.4" is NOT > >> a valid address. It should instead be written as "user@[1.2.3.4]" > > On 30.10.13 17:53, RW wrote: > >If you are referring to 4.1.3. I would say it's defining a routing > >mechanism rather than limiting what a valid address is. > > 4.1.2 defines it as part of mail address: > > address-literal = "[" ( IPv4-address-literal / > IPv6-address-literal / > General-address-literal ) "]" > > Mailbox = Local-part "@" ( Domain / address-literal )
But does anything actually say that 1.2.3.4 can't be treated as a hostname. Isn't the point of the [] to be a hint to the server that it can treat the contents as an IP address and deliver to that address. I don't see anything obviously wrong with something like no-reply@1.2.3.4
