• Blackmist@feddit.uk
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    4 days ago

    I don’t think it really matters what the standard is, because you’ll be completely limited by some 25 year old bit of Regex from Stack Overflow that every web developer ever has implemented into their form sanity checks.

    • Frezik@lemmy.blahaj.zone
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      4 days ago

      The main one that gets passed around will match the weirdness fine. In fact, it probably matches things you don’t want, anyway.

      A signin/registration form really only needs to do sanity checks to get rid of obviously bad addresses. You’ll have to send a round-trip email confirmation message to make sure the email is real, anyway, so why bother going into great detail? Just check that there’s an ‘@’ symbol and a dot in the domain. Most of the rest is wanking off.

      • Dremor@lemmy.world
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        4 days ago

        A domaine without tld (me@home) is a valide address. I saw an email server being used as a mqtt-like server this way (it is very old and predate those software).

        • Frezik@lemmy.blahaj.zone
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          4 days ago

          An address without a domain is irrelevant for a signin/registration form. Which is like 90% of the code being written in the wild to validate addresses.

          If you’re writing an email server, then you need to care about all these details. Most of us never will.

  • pyre@lemmy.world
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    3 days ago

    nice. though valid but obsolete is not a thing… if it’s obsolete it’s invalid.

    • tyler@programming.dev
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      4 days ago

      You shouldn’t be validating emails yourself anyway. Use a library or check for only the @ and then send an email confirmation.

      • zurohki@aussie.zone
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        4 days ago

        Even if it’s a completely valid address and the domain exists, they still might’ve fat fingered the username part. Going to extreme lengths to validate email addresses is pointless, you still have to send an email to it anyway.

        • psud@aussie.zone
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          3 days ago

          I seem to have annoyed an admin of an instance enough for them to subscribe my signup email to hundreds of dating profiles (presumably using a service that offers to harass someone for you)

          Many of them aren’t good at validating email

          One in ten has one email arrive, asking me to click a link to confirm

          9 in ten have 5 emails before I notice them:

          • Please click a link to confirm
          • You received a wink
          • You received a wink
          • You received 3 chat requests
          • You received a link

          So it’s important to not send emails beyond the validate one to unvalidated addresses, to perfect your service annoying or harassing this parties

          Also, use a disposable address for signing up to Lemmy

  • codapine@lemmy.zip
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    3 days ago

    Also as the registrant of one of those new fancy TLDs, much like the owner of this website (email.wtf), their own email addresses will fail those stupid email validation checks that only believe in example@example.[com|net|org]

    Shitty websites will fail “example@email.wtf”, guaranteed - despite it being 100% valid AND potentially live.

    Source - I have a “.family” domain for my email server. Totally functional, but some shitty websites refuse to believe it.

    • BlushedPotatoPlayers@sopuli.xyz
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      3 days ago

      I have a spam collecting address @freemail.hu , the domain is live and working since 96, sometimes it’s not accepted, because it’s not Gmail I guess

    • notarobot@lemmy.zip
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      3 days ago

      I’m not sure I blame the sites. The spec is so complex that it’s not even possible to know which regex to use

      • bignose@programming.dev
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        2 days ago

        The spec is so complex that it’s not even possible to know which regex to use

        Yes. Almost like a regex is not the correct tool to use, and instead they should use a well-tested library function to validate email addresses.

        • notarobot@lemmy.zip
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          Exactly! But its not obvios. So most of those shitty websites don’t even know they have a problem.

          Then there are also people ignoring it on purpose. I once read a reddit comment saying 'well of your address looks like “John wick 🐶❤️”@2001:0db8:85a3:0000:0000:8a2e:0370:7334 I don’t event want your email in my DB because oit will break something

      • ulterno@programming.dev
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        2 days ago

        I have a feeling, the ones codapine is stating, didn’t even care to half-read the spec and just went with what they knew from experience.
        Maybe they didn’t even know there was a spec.
        Maybe they asked ChatGPT for the regex.

        • notarobot@lemmy.zip
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          3 days ago

          That’s one very random place to find that. There are a lot of different one and there is no way we all just agree to use that one.

          Look art his site that shows a more complete and (in theory) official website. While also explaining that there is no regex that is perfect

          https://emailregex.com/

          (Compete regex for the lazy)

          (?:\[a-z0-9!#$%&'\*+/=?^\_\`{|}\~-]+(?:\\.\[a-z0-9!#$%&'\*+/=?^\_\`{|}\~-]+)\*|"(?:\[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\\\\[\x01-\x09\x0b\x0c\x0e-\x7f])\*")@(?:(?:\[a-z0-9]\(?:\[a-z0-9-]\*\[a-z0-9])?\\.)+\[a-z0-9]\(?:\[a-z0-9-]\*\[a-z0-9])?|\\\[(?:(?:25\[0-5]|2\[0-4]\[0-9]|\[01]?\[0-9]\[0-9]?)\\.){3}(?:25\[0-5]|2\[0-4]\[0-9]|\[01]?\[0-9]\[0-9]?|\[a-z0-9-]\*\[a-z0-9]:(?:\[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\\\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\\])
          
    • lemmyng@piefed.ca
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      4 days ago

      13/21 here. Mostly got hung up on several “this was valid in earlier RFC, and later removed” kind of situations. There are several where I picked the correct answer, but where I know many websites that won’t accept it as valid, and that’s not even the more esoteric ones.

      • NaibofTabr@infosec.pub
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        4 days ago

        Yeah I feel like the correct answer for anything obsoleted by a more recent RFC should be “Invalid”.

        • JohnEdwa@sopuli.xyz
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          4 days ago

          But they will work, and according to the spec, you have to build your system so that it can handle those cases. Obsolete doesn’t mean incorrect or invalid, just a “you shouldn’t do this any more”.

          Obsolete Syntax
          Earlier versions of this standard allowed for different (usually more liberal) syntax than is allowed in this version. Also, there have been syntactic elements used in messages on the Internet whose interpretation have never been documented. Though some of these syntactic forms MUST NOT be generated according to the grammar in section 3, they MUST be accepted and parsed by a conformant receiver.

          https://datatracker.ietf.org/doc/html/rfc2822#section-4

          • Frezik@lemmy.blahaj.zone
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            4 days ago

            Some of those “obsolete” things are outright blocked for specific reasons. For example, routing addresses through multiple servers. It was abused by spammers, so it’s almost always denied these days.

            Looks like this:

            <@foo.example.com@bar.example.com:123@example.com>
            
          • NaibofTabr@infosec.pub
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            3 days ago

            Well shit, yeah, that “MUST be accepted and parsed” is pretty explicit. That sucks. What is even the point of revising standards? How the fuck do we ever get rid of some of these bad ideas?

  • isaacd@lemmy.world
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    4 days ago

    Let us recite the email validator’s oath:

    If it has something before the @, something between the @ and the ., and something after the ., it’s valid enough.

      • isaacd@lemmy.world
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        3 days ago

        No. The number of users who have a real email with no TLD is far less than the number of users who will accidentally type an email with no TLD if you don’t validate on the front end.

        I’m here to help 99.9% of users sign up correctly, not to be completely spec-compliant for the 0.1% who think they’re special.

        • ulterno@programming.dev
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          2 days ago

          Guess my mail@IPv6 won’t be accepted because I was too poor to pay for a domain name after having paid for a static IPv6.

  • CommanderCloon@lemmy.ml
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    3 days ago

    Question 5 is incorrect, name@example is a fully valid email address, even after RFC 2822

    The spec of RFC 2822 defines an address (3.4.1) as:

    local-part "@" domain
    

    domain is defined (3.4.1) as:

    domain = dot-atom / domain-literal / obs-domain
    

    dot-atom is defined (3.2.4) as:

    dot-atom = [CFWS] dot-atom-text [CFWS]
    dot-atom-text = 1*atext *("." 1*atext)
    

    1*atext meaning at least 1 alphanumeric character, followed by *("." 1*atext) meaning at least 0 "." 1*atext


    If tomorrow, google decided to use its google top-level domain as an email domain, it would be perfectly valid, as could any other company owning top-level domains

    Google even owns a gmail TLD so I wouldn’t even be surprised if they decided to use it

    • HereIAm@lemmy.world
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      4 days ago

      I don’t know if they changes the answer to the question, but it now says name@example is valid.

      • CommanderCloon@lemmy.ml
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        4 days ago

        It does say it’s valid, but also that it’s obsolete, and while the RFC does define valid but obsolete specs, there is nothing defining domains without a dot as obsolete, and it is in fact defined in the regular spec, not the obsolete section

      • snooggums@lemmy.world
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        4 days ago

        It says valid but obsolete, which sounds like a contradiction to me.

        This is technically valid but considered obsolete. RFC 822 allowed domains without dots, but RFC 2822 made this obsolete.

        Do email suffix not indicate a different domain like .org and .com for websites?

  • irish_link@lemmy.world
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    4 days ago

    THIS THING IS STUPID!!!

    Or it’s just me that is the fool. Thanks for sharing. I just learned about 9 new things.

    • rtxn@lemmy.world
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      4 days ago

      All of the modern internet is built on the decaying carcasses of temporary solutions and things that seemed like a good idea at the moment but are now too widely used to change.

  • ikidd@lemmy.world
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    4 days ago

    I gave up when I got like 5 wrong. I’ve ran mail servers for decades, most of the invalid “valids” would get rejected by any mailservers I’ve administered.

  • TomasEkeli@programming.dev
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    4 days ago

    I don’t validate emails, I test them.

    That’s your email? OK, what did we send it? if we couldn’t send to it or the user can’t read it there’s no reason to accept it.

    OK, maybe I do some light validation first, but I don’t trust the email address just because it’s email-address-shaped.

    • GiveOver@feddit.uk
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      3 days ago

      Hooray, you have better security than Apple, who won’t let me use my own email because some idiot in Australia used it first.

  • rumba@lemmy.zip
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    4 days ago

    I lost it at the fork bomb. I mean I hit valid because there was no way it was on the and not valid, but there’s no way i’d have expected that. after that I just kept guessing the most stupid answer and did pretty well