[Oberon] Re (4): Duplicate headers in SMTP.

[peter at easthope.ca]

From:	Michael Schierl <schierlm at gmx.de>
Date:	Fri, 22 Jul 2022 23:54:41 +0200
> "To:" may only appear once.

Ug!  Used email for more than three decades without recognizing that 
https://datatracker.ietf.org/doc/html/rfc5322#section-3.6 
allows no more than one of each of to, cc and bcc fields.  =8~/

From:	Paul Reed <paulreed at paddedcell.com>
Date:	Fri, 22 Jul 2022 22:57:20 +0100
> "Oh, it's worse than that, Jim!" :)

Star Trek?  Yes, definitely worse.  =8~(  

Certainly Oberon mail output should respect IETF.

From:	Michael Schierl <schierlm at gmx.de>
> Try:
> 
> To: <...... at gmail.com>, <s.... at shaw.ca>

Here Mail is compiled with simpler = TRUE.  <> are omitted.

For input, I'd rather Oberon accept
To: a at m
To: b at n
and 
Bcc: c at p
Bcc: d at q
than require
To: a at m, b at n
and
Bcc: c at p, d at q
.

The former is better to read. In the Oberon interface, better to 
assemble. Also the IETF limits and recommends line lengths.  
https://datatracker.ietf.org/doc/html/rfc5322#section-2.1.1

In fact
Bcc: c at p
Bcc: d at q
Bcc: e at r
  ...
rarely fails.  I've used lists of forty or more addresses without a 
failure.  It's
To: a at m
To: b at n
which snags.

From:	Paul Reed <paulreed at paddedcell.com>
> The code ... will need a good coat of looking at, to reduce the 
> number of "TO:" headers to one. :(

Another project ... but admire the progress of ETH Oberon over a 
decade ago.

Regards,                    ... P.L.