this post was submitted on 18 Aug 2025
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Everyone knows what an email address is, right? (Quiz) (e-mail.wtf)
submitted 4 days ago by TheBigRoomXXL@leminal.space to c/programmer_humor@programming.dev
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[–] CommanderCloon@lemmy.ml 61 points 4 days ago* (last edited 3 days ago) (2 children)

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 26 points 4 days ago (2 children)

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

[–] CommanderCloon@lemmy.ml 34 points 4 days ago (1 children)

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

[–] HereIAm@lemmy.world 13 points 4 days ago

I see what you mean, I'm with you now.

[–] spankmonkey@lemmy.world 6 points 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?

[–] pineapplelover@lemmy.dbzer0.com 3 points 4 days ago* (last edited 4 days ago) (3 children)

I didn't understand this one. How do you have a no dot domain? Like you need to distinguish from example.com or example.wtf

Edit: do you mean if you own .google you can have your email@google address?

[–] DaPorkchop_@lemmy.ml 5 points 4 days ago

Yes, the top-level domain is still just a domain. I'm not aware of any public Internet services which are reachable from a TLD directly, and it's strongly discouraged by ICANN, but there isn't any technical limitation preventing e.g. someone at Verisign from setting up example@com.

[–] mobotsar@sh.itjust.works 2 points 3 days ago* (last edited 3 days ago) (1 children)

In response to your edit.

Yes, or countries could use their cctld, e.g. email@us or noreply@uk.

Or any tld owner could do the same with theirs, of course.

[–] Atherel@lemmy.dbzer0.com 1 points 3 days ago

you could also send mails within your local network, the hostname just has to resolve and have a mail service running