Everyone knows what an email address is, right? (Quiz)
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I can't even view it...I get a TLS error
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14 / 21
This is the score you get when you answer "valid" for every question. Good job.
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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.
Emoji domains can be registered using punycode, and you're right that it's up to the TLD whether they're allowed or not.
For example: http://
.la/
.la is encoded using punycode to http://
.la/
is URL-encoded to %F0%9F%90%B6
Giving the 'true' URL http://
.la/
which then redirects to https://emojipedia.org/dog-face
Emails should generally use
@xn--yt8h.la
instead of@📙.la
for maximum compatibility. I'm not sure if the email spec allows punycode. -
#18 seems really bad, like no-one-has-ever-sanity-checked-this bad.
Im still trying to figure out what that means. How does @ resolve to an IP address?
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Relevant talk from FOSDEM 2018 (warning: poor audio quality): https://youtu.be/xxX81WmXjPg
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This post did not contain any content.wrote last edited by [email protected]
::: spoiler My top five from this (all valid):
- ":(){␣:|:&␣};:"@example.com # fork bomb
@
and poop@[
]
- "@"@[@]
- c̷̨̈́i̵̮̅l̶̠̐͊͝ȁ̷̠̗̆̍̍n̷͖̘̯̍̈͒̅t̶͍͂͋ř̵̞͈̓ȯ̷̯̠-̸͚̖̟͋s̴͉̦̭̔̆̃͒û̵̥̪͆̒̕c̸̨̨̧̺̎k̵̼͗̀s̸̖̜͍̲̈́͋̂͠@example.com
- fed-up-yet@␣example.com␣ # ␣ = whitespace
:::
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I had to make an email address just for paypal because those idiots don't accept subdomains in email addresses.
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Yeah I feel like the correct answer for anything obsoleted by a more recent RFC should be "Invalid".
wrote last edited by [email protected]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. -
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::: spoiler Tap for spoiler
Email addresses can have comments?!
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14 / 21
This is the score you get when you answer "valid" for every question. Good job.
I didn't do that but got 14 anyway.
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I didn't do that but got 14 anyway.
Also didn't do that, but that was the text
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::: spoiler My top five from this (all valid):
- ":(){␣:|:&␣};:"@example.com # fork bomb
@
and poop@[
]
- "@"@[@]
- c̷̨̈́i̵̮̅l̶̠̐͊͝ȁ̷̠̗̆̍̍n̷͖̘̯̍̈͒̅t̶͍͂͋ř̵̞͈̓ȯ̷̯̠-̸͚̖̟͋s̴͉̦̭̔̆̃͒û̵̥̪͆̒̕c̸̨̨̧̺̎k̵̼͗̀s̸̖̜͍̲̈́͋̂͠@example.com
- fed-up-yet@␣example.com␣ # ␣ = whitespace
:::
Spoilers!
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This post did not contain any content.wrote last edited by [email protected]
Question 5 is incorrect,
name@example
is a fully valid email address, even after RFC 2822The 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 domainsGoogle even owns a
gmail
TLD so I wouldn't even be surprised if they decided to use it -
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I scored 13/21 on https://e-mail.wtf/ and all I got was this lousy text to share on social media.
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This post did not contain any content.wrote last edited by [email protected]
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:
<@[email protected]:[email protected]>
But this is almost always denied on modern email servers because it was abused by spammers.
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14 / 21
This is the score you get when you answer "valid" for every question. Good job.
My score was lower
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I had to make an email address just for paypal because those idiots don't accept subdomains in email addresses.
Pizza Hut doesn't allow dashes in the domain. This prevents me from ordering Pizza Hut with the email under my personal domain. This can be considered a feature.
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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.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:
<@[email protected]:[email protected]>
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Yeah I feel like the correct answer for anything obsoleted by a more recent RFC should be "Invalid".
Complaints about the quiz? Send them to
@
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Question 5 is incorrect,
name@example
is a fully valid email address, even after RFC 2822The 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 domainsGoogle even owns a
gmail
TLD so I wouldn't even be surprised if they decided to use itI don't know if they changes the answer to the question, but it now says
name@example
is valid.