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Design Issue Register with german umlaut in e-mail domain

Discussion in 'Resolved Bug Reports' started by rhs, Jun 9, 2016.

  1. rhs

    rhs Member


    there is no registration possible if the Email adress has a german umlaut in the domain name:


    The same Problem is with the IDN from this domain (info@xn--wrth-0ra.de as example).

    genesisraley likes this.
  2. HWS

    HWS Well-Known Member

    Domains with special characters should generally not be used for e-mail. Most e-mail servers cannot handle such e-mail addresses and therefore many mails won't reach their receipients.

    I don't know if this should be considered as a bug in Xenforo.
    Terror likes this.
  3. rhs

    rhs Member

    Then the relevant e-mail server are configured incorrectly ... But that is not the problem, the problem is a bug in XF.
  4. teletubbi

    teletubbi Active Member

    This i don't belive.
    Because this is a domain from a big company in germany.
    So all their customers and suppliers had problems.

    And if this would happen they had changed their domain already.

    By the way i got emails from them as well.
  5. Mike

    Mike XenForo Developer Staff Member

    The umlaut version being rejected is generally expected and not something I expect to change. By definition, it's not a valid domain name so it's not a valid email. That's where the punycode representation comes in.

    However, the punycode version being rejected is a bug.
    Snog likes this.
  6. Snog

    Snog Well-Known Member

    Last edited: Jun 9, 2016
  7. rhs

    rhs Member

    Why not? XF is used worldwide, you should not build artificial barriers ... ;).

  8. Xon

    Xon Well-Known Member

    As RFC3490 says:
    Relevant email IDN RFCs: https://tools.ietf.org/html/rfc6531

    It isn't well supported since you need quite recent versions of the email server software.
  9. Mike

    Mike XenForo Developer Staff Member

    I'm going to confirm this for now, but I'm unsure what the resolution will be. In the email validation library (which is part of Zend Framework), the hostname validation converts the Punycode domain into the UTF-8 version before validating. We have explicitly disabled validation of the UTF-8 version (due to a previous bug report where this didn't work as an email target anyway). Annoyingly, this ends up disabling the Punycode version because of that conversion (and another check that would block it even without the conversion).

    The realistic fix is to allow IDN validation, but ensure the email is always coerced to an the Punycode version before use/storage. This may not be something viable in the short term.

    It's worth noting that the change that ended up disabling IDNs was made over a year ago. It doesn't seem like there's a huge demand for it.
  10. Mike

    Mike XenForo Developer Staff Member

    As it stands, this isn't something that is going to be a simple fix with our email validation methods. If you or your users have run into this legitimately, then it would be useful to hear, but as it stands, it has only come up in a couple occasions.

    As such, we're tagging this as a design issue. (Worth noting that it's a moot point in XF2 since we are using different email validation code.)

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