> stripped of dots and other inert punctuation
The period thing is a Gmail feature, not a standard. some.email@mydomain and someemail@mydomain most certainly do not deliver to the same mailbox.
The period thing is a Gmail feature, not a standard. some.email@mydomain and someemail@mydomain most certainly do not deliver to the same mailbox.
For example, a malicious user can register
some.email@gmail.com
so.meemail@gmail.com
someem.ail@gmail.com
so.mee.mail@gmail.com
somee.mail@gmail.com
so..mee.mail@gmail.com
som..eem.ail@gmail.com
so.meemail@gmail.com
somee.mail@gmail.com
And the only way it can be automated is if the service doesn't protect itself against automated user sign-ups, which they will either start doing once someone really takes advantage of it, or will result in their domain being categorised as spam once they start sending lots of sign-up emails (either by the user or gmail in general).
What is a problem, and what is non-standards-compliant, is GitHub incorrectly assuming that all mail providers will do this when many do not. It would be no different from assuming that "admin" and "postmaster" go the same mailbox because that's the way a lot of software is configured.
That's why we keep your verified mailbox address for sending mail; but there's no good reason to consider them different for the purpose of identity.
A false postive in these identity checks is likely to be less destructive than a false negative. But I still don't get the point of making up all sorts of rules not in the standard. I have seen both + as well as meaningful dots in e-mail adresses in the wild.
Google was the first installation I know of to silently swallow periods. Plus-addressing was well-known back in the day, but as far as I know GUI mailers more or less killed the practice by not offering support for it, and web sites written by people too smart to know how to validate email addresses ensured you can't even use them properly anymore.
Ref: http://www.faqs.org/rfcs/rfc822.html, pages 8/9.
Both of Microsoft's own identity services (AAD and Live ID, and by extension O365 and Outlook.com) recognize (and allow creation of) microcolonel@example.com, micro.colonel@example.com, and mic.rocolonel@example.com as distinct identities/email addresses.
What you're saying is that once the first of (microcolonel|micro.colonel|mic.rocolonel)@example.com registers at github, the other two will no longer be able to do so, but will instead receive a confusing 'you already have an account' error, (hopefully) without being able to receive password reset emails.