[Users] Address book defaults to lower case

[Dave Howorth]

On Wed, 22 Mar 2017 11:55:35 +0100
Andrej Kacian <andrej at kacian.sk> wrote:

> On Wed, 22 Mar 2017 10:11:25 +0000
> Brian Morrison <bdm at fenrir.org.uk> wrote:
> 
> > On Wed, 22 Mar 2017 10:34:06 +0100
> > wwp wrote:
> > 
> > > I can't believe a server wants capitalized names in email
> > > addresses (or case sensitiveness in general). Would you show us
> > > the error thrown by this server?
> > 
> > Actually folks, the local part of the address before the @ should
> > have case preserved, there are people who do use capitalized
> > addresses in this way.
> > 
> 
> You are both correct and incorrect (as is frequently the case with
> RFCs).
> 
> RFC 2821[1] manages to contradict itself. In section 2.4, it says:
> 
>    [...] The local-part of a mailbox
>    MUST BE treated as case sensitive.  Therefore, SMTP implementations
>    MUST take care to preserve the case of mailbox local-parts.
> Mailbox domains are not case sensitive.  In particular, for some
> hosts the user "smith" is different from the user "Smith".  However,
> exploiting the case sensitivity of mailbox local-parts impedes
> interoperability and is discouraged.
> 
> Then later, in section 4.1.2:
> 
>    While the above definition for Local-part is relatively permissive,
>    for maximum interoperability, a host that expects to receive mail
>    SHOULD avoid defining mailboxes where the Local-part requires (or
>    uses) the Quoted-string form or where the Local-part is case-
>    sensitive.
> 
> Arguably, "MUST" takes precedence over "SHOULD".

But in particular, the part in 2.4 does apply to claws, does it not? In
terms of the address book, it must treat the local part as
case-sensitive.

Of course it can also comply with 4.1.2 in terms of mailboxes that it
defines. The two sections are not contradictory.

Or have I misunderstood something?

> 1. https://tools.ietf.org/html/rfc2821
> 
> Regards,