The RFC does not specifically disallow case-insensitive email addresses, no.
This all feels like a moot point. Messing with user data (read: not rejecting it) before it hits the database for ‘technical’ reasons is certainly swimming against the tide. You hardly ever see it these days. If you need case-insensitive comparison of email addresses (e.g. for an auth check), then just do a case-insensitive comparison. This is why things like CI[Text/Char/Email]Field exist. If we are appealing to authority, Gmail’s new account sign up form preserves user case. Kye On 13 Dec 2021, 12:52 PM +0800, אורי <u...@speedy.net>, wrote: > Hi, > > As far as I know, Google, which runs mail servers for about 85% of users > worldwide (Gmail + Workspace users), email addresses and usernames are case > insensitive. So if you send me for example an email to u...@speedy.net, I > will receive it. Although according to the RFC it should have been bounced > (actually I'm not sure, maybe it's up to the domain manager (speedy.net / > gmail.com) to decide if to bounce it or not). This is a de-facto standard - I > know companies that always send me mail to my email address in uppercase, and > I think they do it to all of their customers. I don't think they have > delivery problems with customers. > > אורי > u...@speedy.net > > > > On Mon, Dec 13, 2021 at 6:39 AM Benny <be...@twosensedesign.com> wrote: > > > That’s a matter of perspective - RFC 5321 documents it pretty well. While > > > I agree that, speculatively, the majority of servers may normalize emails > > > to lower-case, it’s not officially recognized. I’m a fan of exhaustive > > > documentation, but this is a standard set by an arguably higher authority. > > > > > > Benny > > > > > > > On Dec 12, 2021, at 10:15 PM, Arthur Pemberton <pemb...@gmail.com> > > > > wrote: > > > > > > > > The current behaviour is an undocumented gotcha. It should at least be > > > > mentioned in the documentation. Very few major login based platforms > > > > are case sensitive, so it should be at least mentioned in the > > > > documentation that by default applications built with Django would be > > > > different in that regard. > > > > > > > > Arthur > > > > > > > > > On Sun, 12 Dec 2021 at 23:01, Benny <be...@twosensedesign.com> wrote: > > > > > > IMO this treads dangerously close to what I call a “Django Gotcha” > > > > > > - There exist some implementations, where if you’re not paying > > > > > > attention, it’ll come back to bite you in the keister. One example > > > > > > would be the test runner coercing DEBUG=False in an effort for > > > > > > tests to more accurately reflect a production environment. > > > > > > > > > > > > Normalization is a nightmare all on its own without having to > > > > > > implicitly introduce it. > > > > > > > > > > > > Benny > > > > > > > > > > > > > On Dec 12, 2021, at 9:40 PM, Kye Russell <m...@kye.id.au> wrote: > > > > > > > > > > > > > > Strong -1 on overriding user intent on capitalisation, especially > > > > > > > for email addresses as the RFC stipulates that the local part of > > > > > > > an email address is case sensitive, this is just rarely > > > > > > > practiced. There are much better solutions out there > > > > > > > (CI[Text|Char]FIeld in Postgres, etc) that enforce > > > > > > > case-insensitivity purely for comparison operations which is > > > > > > > where you really want it, but without overriding user intent wrt > > > > > > > what case the user wants to use in their email or username. > > > > > > > > > > > > > > Django could maybe do with easing the process of implementation > > > > > > > for case-insensitive fields outside of Postgres. I’m not familiar > > > > > > > enough with the other RDBMSs to know how workable that is. But > > > > > > > the answer is certainly not discarding user intent. > > > > > > > > > > > > > > Kye > > > > > > > On 13 Dec 2021, 11:32 AM +0800, Arthur Pemberton > > > > > > > <pemb...@gmail.com>, wrote: > > > > > > > > A setting to convert all usernames to lowercase would be good > > > > > > > > too -- that's my preference overall in general. However I > > > > > > > > haven't yet seen how best that could/would be accomplished. > > > > > > > > > > > > > > > > For simpler uses case where I'm just sub-classing AbstractUser > > > > > > > > and not customizing the auth backend, I've taken to overriding > > > > > > > > UserManager.get_by_natural_key to allow for case-insensitive > > > > > > > > logins. Though really, I probably should add a signal handler > > > > > > > > to force username to lowercase. > > > > > > > > > > > > > > > > Arthur > > > > > > > > > > > > > > > > > On Sunday, December 12, 2021 at 11:21:32 AM UTC-5 Uri wrote: > > > > > > > > > > Hi Arthur, > > > > > > > > > > > > > > > > > > > > I would recommend users of Django to use only lowercase > > > > > > > > > > usernames. And if they insist that the username is an email > > > > > > > > > > address, also convert it to lowercase. Otherwise you can > > > > > > > > > > have 3 separate users uri, Uri, and uRI, or 3 separate > > > > > > > > > > users with email addresses u...@example.com, > > > > > > > > > > u...@example.com, and u...@example.com (or even > > > > > > > > > > u...@example.com). Maybe it's better to add an optional > > > > > > > > > > setting to enforce usernames to be lowercase. And by the > > > > > > > > > > way also alphanumeric. You don't want "!@#" to be a > > > > > > > > > > username on your system (or the user's name in Chinese or > > > > > > > > > > Hebrew). > > > > > > > > > > > > > > > > > > > > It's interesting that this ticket is 15 years old and still > > > > > > > > > > not completely resolved. > > > > > > > > > > > > > > > > > > > > By the way, when people type their email address, some > > > > > > > > > > programs (including browsers) convert the first letter to > > > > > > > > > > uppercase, and I have received email addresses from people > > > > > > > > > > with the first letter in uppercase, although their true > > > > > > > > > > address is lowercase. I don't think you want this uppercase > > > > > > > > > > letter to appear on your database in the email field. > > > > > > > > > > > > > > > > > > > > אורי > > > > > > > > > > (Uri) > > > > > > > > > > > > > > > > > > > > u...@speedy.net > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sun, Dec 12, 2021 at 6:02 PM Arthur Pemberton > > > > > > > > > > > <pem...@gmail.com> wrote: > > > > > > > > > > > > Especially with the ability to set USERNAME_FIELD to > > > > > > > > > > > > "email", it would be really useful to at least have a > > > > > > > > > > > > well documented warning that usernames are > > > > > > > > > > > > case-sensitive in Django. > > > > > > > > > > > > > > > > > > > > > > > > I've been using Django for years, and even I forget > > > > > > > > > > > > that fact some times. Until I start Googling and come > > > > > > > > > > > > across [1]. > > > > > > > > > > > > > > > > > > > > > > > > Ideally, it would be great to have a setting (or model > > > > > > > > > > > > field) that would allow easy switching to case > > > > > > > > > > > > insensitive usernames. > > > > > > > > > > > > > > > > > > > > > > > > Arthur Pemberton > > > > > > > > > > > > > > > > > > > > > > > > ---- > > > > > > > > > > > > > > > > > > > > > > > > [1] https://code.djangoproject.com/ticket/2273 > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > You received this message because you are subscribed to > > > > > > > > > > > > the Google Groups "Django developers (Contributions to > > > > > > > > > > > > Django itself)" group. > > > > > > > > > > > > To unsubscribe from this group and stop receiving > > > > > > > > > > > > emails from it, send an email to > > > > > > > > > > > > django-develop...@googlegroups.com. > > > > > > > > > > > > To view this discussion on the web visit > > > > > > > > > > > > https://groups.google.com/d/msgid/django-developers/9a5e1df3-778d-4993-8c32-57870fafd8f9n%40googlegroups.com. > > > > > > > > > > > > > > > > -- > > > > > > > > You received this message because you are subscribed to the > > > > > > > > Google Groups "Django developers (Contributions to Django > > > > > > > > itself)" group. > > > > > > > > To unsubscribe from this group and stop receiving emails from > > > > > > > > it, send an email to > > > > > > > > django-developers+unsubscr...@googlegroups.com. > > > > > > > > To view this discussion on the web visit > > > > > > > > https://groups.google.com/d/msgid/django-developers/c2bb1b2f-e1ac-4770-8989-ebb0fdc47a2cn%40googlegroups.com. > > > > > > > > > > > > > > -- > > > > > > > You received this message because you are subscribed to the > > > > > > > Google Groups "Django developers (Contributions to Django > > > > > > > itself)" group. > > > > > > > To unsubscribe from this group and stop receiving emails from it, > > > > > > > send an email to django-developers+unsubscr...@googlegroups.com. > > > > > > > To view this discussion on the web visit > > > > > > > https://groups.google.com/d/msgid/django-developers/2b02d741-e49d-486e-b92d-92d0e233b9e9%40Spark. > > > > > > > > > > > > > > > > > > -- > > > > > > You received this message because you are subscribed to the Google > > > > > > Groups "Django developers (Contributions to Django itself)" group. > > > > > > To unsubscribe from this group and stop receiving emails from it, > > > > > > send an email to django-developers+unsubscr...@googlegroups.com. > > > > > > To view this discussion on the web visit > > > > > > https://groups.google.com/d/msgid/django-developers/874D59C4-0933-44A1-AF38-AAF6A0F554A8%40twosensedesign.com. > > > > > > > > -- > > > > You received this message because you are subscribed to the Google > > > > Groups "Django developers (Contributions to Django itself)" group. > > > > To unsubscribe from this group and stop receiving emails from it, send > > > > an email to django-developers+unsubscr...@googlegroups.com. > > > > To view this discussion on the web visit > > > > https://groups.google.com/d/msgid/django-developers/CA%2BX4dQTSxY%3DZNd0Tvo7ogYv-10ecXz4RuuFUXGcLV0-J7J7gEg%40mail.gmail.com. > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "Django developers (Contributions to Django itself)" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to django-developers+unsubscr...@googlegroups.com. > > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/django-developers/BCE93C94-A535-444F-BF76-1055FCF9B736%40twosensedesign.com. > -- > You received this message because you are subscribed to the Google Groups > "Django developers (Contributions to Django itself)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to django-developers+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-developers/CABD5YeH1NRx57KZ-Yc%2BEVVMODpgTN6ykRvy1nk08OFiekJQy%2Bg%40mail.gmail.com. -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. 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