Concentration and centralization (was Free software during wartime)

Posted Mar 24, 2023 9:30 UTC (Fri) by gdt (subscriber, #6284)
In reply to: Concentration and centralization (was Free software during wartime) by ballombe
Parent article: Free software during wartime

Noting that this excludes a lot of international domains, such as example.com.au.

It would help if the IETF published a short RFC on this precise point of conformance checks for the current formats of email addresses. Even though that information is available from other RFCs. The RFC could include regexps in common languages for accepting an email address in a form.

Even experienced programmers stuff up addresses like jane+folder@example.com.au and fred@newtld (no dot in RHS) being valid. It's also probably time that the IETF determined if it is still useful that fred@example.com.au and Fred@example.com.au are different addresses, although that will probably end up in weasel works like "may be different mailboxes or may be identical mailboxes".

Concentration and centralization (was Free software during wartime)

Posted Mar 29, 2023 16:57 UTC (Wed) by Wol (subscriber, #4433) [Link] (2 responses)

Fred = fred?

I thought it was canonical (as a result of historical pressure) that email addresses MUST be case insensitive. Back in the dim and distant past, some sites were upper case, some sites were lower case, some transposed all case passing through, and some just didn't have (upper) lower case. I certainly started my programming career unable to use lower case ...

The other big problem we have is "is Jo.Bloggs = jobloggs". I gather Google certainly think so ... so long as it's only gmail addresses that suffer this, then that's okay, but it won't do the wider internet any favours ...

Cheers,
Wol

Concentration and centralization (was Free software during wartime)

Posted Mar 29, 2023 17:43 UTC (Wed) by james (subscriber, #1325) [Link] (1 responses)

Actually, the standards say that:

"an SMTP server supporting mail relaying or delivery MUST support the reserved mailbox "postmaster" as a case-insensitive local name" (RFC 5321 section 4.5.1): emails to postmaster must work from broken systems,
but all other local-parts may be case sensitive.
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. 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.
(RFC 5321 section 2.4)

Nobody actually implements case-sensitive mailboxes, though, because the easiest way to get PoStMaStEr working is making everything case-insensitive, and a number of mailers (historically, at least) upper-cased everything.

Concentration and centralization (was Free software during wartime)

Posted Mar 29, 2023 21:33 UTC (Wed) by anselm (subscriber, #2796) [Link]

Nobody actually implements case-sensitive mailboxes, though

Way back at university in the early 1990s we ran AIX on a bunch of IBM RS/6000 machines. One annoyance that we had to deal with was that IBM's implementation of Sendmail very faithfully enacted the RFC that said local parts of e-mail addresses (except “postmaster”) must be treated as case-sensitive. This together with some professors insisting on capitalising the names in everyone's e-mail addresses led to some fairly sizeable /etc/aliases files. Our IBM rep said that things were working as designed and filing a “program change request” would probably be pointless.