Everyone knows what an email address is, right? (Quiz)

I scored 16/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

This was fun!

Edit: people, upvote the OP, not me

<@foo.example.com@bar.example.com:123@example.com>

THIS THING IS STUPID!!!!

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

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.

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

I don't care who the IRS sends, I am not validating emails with spaces on them.

What if we 👉@👈 ..? 🤭

Two of my "favorite" features it didn't even touch on. You can have nested comments:

foo(one(two(three(four(five(six(seven)))))))@example.com

This will actually fail on that big email regex that gets copied around (originally from Mastering Regular Expressions in 1997), because it can only handle comment nesting to a depth of six. It is actually possible to do indefinite nesting now with recursive regex, but it was developed before that feature existed.

RFC822 also allows routing addresses through multiple servers:

<@foo.example.com@bar.example.com:123@example.com>

But this is almost always denied on modern email servers because it was abused by spammers.

::: spoiler My top five from this (all valid):

• ":(){␣:|:&␣};:"@example.com # fork bomb
• 👉@👈 and poop@[💩]
• "@"@[@]
• c̷̨̈́i̵̮̅l̶̠̐͊͝ȁ̷̠̗̆̍̍n̷͖̘̯̍̈͒̅t̶͍͂͋ř̵̞͈̓ȯ̷̯̠-̸͚̖̟͋s̴͉̦̭̔̆̃͒û̵̥̪͆̒̕c̸̨̨̧̺̎k̵̼͗̀s̸̖̜͍̲̈́͋̂͠@example.com
• fed-up-yet@␣example.com␣ # ␣ = whitespace :::

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.

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.

I had to make an email address just for paypal because those idiots don't accept subdomains in email addresses.

I scored 13/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

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.

I scored 16/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

Damn, and here I thought I had this locked down because I was salty that so many places struggle with + in the email addy. But my god, there's comments?

14 / 21

This is the score you get when you answer "valid" for every question. Good job.

Thanks to RFC 6532, Zalgo text is a-okay.

hmmm...

Yay! You're average! Time to start making plans for what you'll do when an LLM takes your job.

I already have plans.

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

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.

const emailRegExp = /^[\w.!#$%&'*+/=?^`{|}~-]+@[a-z\d-]+(?:\.[a-z\d-]+)*$/i;

(?:\[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])+)\\])

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

13/21, seems like I am not significantly different from random guessing

I scored 16/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

I feel pretty good about that

::: spoiler Tap for spoiler Email addresses can have comments?! :::

13 right answers and I didn't expect so many lol

I'll never validate some of the 💩 I've learnt today.

I scored 14/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

I actually died at the poop emoji one. Actually amazing awareness to test for that

Pretty much everything I've seen in e-mail is needlessly complicated and weird. So of course addresses are as well.

Wow. if I ever have the madness required to self-host, I'll have my email at an IP address.

15

Going to have to try some of those.... Can you actually register emojis as a domain, or is that just the email validation that allows them?

Edit: most TLDs don't. Smaller ones do sometimes.

Relevant talk from FOSDEM 2018 (warning: poor audio quality): https://youtu.be/xxX81WmXjPg

12/21

are things that are considered out of current spec really "valid" though?

I vaguely remember a panel where a guy went through various cases like these.

One of the things that stood out is that not every email provides implements the same specs, so one provider might allow you to set up a "valid" email address that might not be able to communicate with other providers as they consider it "invalid".

Average :/

Jesus effin Christ! I had no idea! This is madness! This is ... Omfg I just can't

I got 13/21. I mean thats not bad 😄

12/21. It was highly entertaining though.

I rage quit gave up at 12.

A fork bomb is apparently a valid email address.

I quit, this is stupid.

Try explaining that last one to someone over the phone

I scored 18/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

If qoutes are removed and internal spaces are invalid, how could ":(){␣:|:&␣};:"@example.com be valid?

You can easily validate e-mail addresses using this simple regex pattern.

:::spoiler regex

(?:(?:\r\n)?[ \t])*(?:(?:(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t]
)+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:
\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(
?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ 
\t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\0
31]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\
](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+
(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:
(?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z
|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)
?[ \t])*)*\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\
r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[
 \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)
?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t]
)*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[
 \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*
)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t]
)+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)
*:(?:(?:\r\n)?[ \t])*)?(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+
|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r
\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:
\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t
]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031
]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](
?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?
:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?
:\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*)|(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?
:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?
[ \t]))*"(?:(?:\r\n)?[ \t])*)*:(?:(?:\r\n)?[ \t])*(?:(?:(?:[^()<>@,;:\\".\[\] 
\000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|
\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>
@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"
(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t]
)*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\
".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?
:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[
\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".\[\] \000-
\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(
?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;
:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([
^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\"
.\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\
]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\
[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\
r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] 
\000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]
|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)?(?:[^()<>@,;:\\".\[\] \0
00-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\
.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,
;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?
:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*
(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".
\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[
^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]
]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*)(?:,\s*(
?:(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\
".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(
?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[
\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t
])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t
])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?
:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|
\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?:
[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\
]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*\<(?:(?:\r\n)
?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["
()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)
?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>
@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\r\n)?[
 \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,
;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t]
)*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\
".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)?
(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".
\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:
\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\[
"()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])
*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])
+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\
.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z
|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(
?:\r\n)?[ \t])*))*)?;\s*)

:::

I can't even view it...I get a TLS error

17/21. Would have been 18 but the first example of spaces screwed me.

I scored 12/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

I scored 16/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

I scored 13/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

15/21

Well... like Bill Clinton said, it depends on what the definition of "is" is.

So much better than I thought it would be! Thank you for making the world a better & more informed place

#18 seems really bad, like no-one-has-ever-sanity-checked-this bad.

I scored 12/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media. That was absolutely hilarious!

I kind of expected a lot of this; I remember the sendmail 4 book from back in the day when O'Reilly had that, DNS and BIND, and Perl as the entirety of its corpus.

And after that, I now can't wait for the next pull request with a regular expression on email validation to come through.

I scored 15/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.

brb omw to try and reserve 👉@👈 as e-mail address

I did not like this and quit after ten questions 😅

But I respect that it exists.