Re: [ietf-smtp] Valid RFC5322 address

[Hector Santos <[e-mail]>]

On 5/3/2020 11:57 AM, John C Klensin wrote:
>
> Technically, no.  The "/" is not a problem.  Colons are (they
> are not in the list of valid characters for <atext> in RFC
> 5322), I imagine at least in part because they were part of the
> now-discouraged Source Route syntax (see Sections 3.6 and
> Appendix C of RFC 5321 (and 5321bis, at least so far)) and so
> would need to be quoted.

Just from a reader pov, it wasn't quote clear between the two docs. I 
see now RFC5322 is defining atext clearly.  RFC5321 probably needs a 
reference to RFC5322 for atext.

> Noting that you seem to be turning blanks into ".",

Yes, from the old MHS methods that took local user names, i.e. "Hector 
Santos" and dotted/underscored them when networking came to BBSes.

char *MakeDotName(char *psz)
{
   char *p = psz;
   while (*p) {
     switch (*p) {
       case ' ': *p = '.'; break;
       case '.': *p = '_'; break;
     }
     p++;
   }
   return psz;
}

>I'd also
> want to be careful to be sure that any value "." characters to
> the right of the "/" in your example don't get broken by any
> de-conversion process.

I see.

> Also note that, if this is going to be used in conjunction with
> web facilities, someone is likely to want to turn whatever you
> produce into a MAILTO: URL and restrictions on those (both
> restrictions imposed by the spec and those imposed by sloppy
> implementations) are even worse.
>
> ...
>
> Recommendation: Don't push it.


+1, I plan to change it.  It was initially meant to be more for local 
MUAs (Not networking). Then the notify by email was added where there 
is a MakeDotName() translation and no consideration for special 
characters.  I think I will first try this for the local name to email 
name translation.

   "Github Agent: github-hookshot/xxxxxxxxx" [e-mail]

And check how Apple's web-based MUA handles it.  Btw, the Apple iPhone 
Mail App display the field fine.

I am also going to an wcSMTP server option to validate the local part 
of the return address.

Thanks

-- 
HLS