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0 pointsPxtl8y ago0 comments

Yup. The most email validation I evern implement is "there must be an @ sign with stuff before and after the @ sign". Maybe require a dot in the latter space.

0 comments

vlunkr8y ago

I know lots of developers (myself included) who thought they could write a functional email regex. Eventually you learn that in the end, the way to validate an email address is to send an email.

OJFord8y ago

> Eventually you learn that in the end, the way to validate an email address is to send an email.

In my experience as a user, most people in the end also validate the email address by sending an email, but do no learning.

benchaney8y ago

Strictly speaking, the dot in the latter space isn't actually necessary. It needs to be a resolvable domain, but if you bought a TLD you could be "name@tld"

bitJericho8y ago

I don't think an @domain is required if it's an email address on the same mail server.

OJFord8y ago

That certainly used to work on Gmail; I haven't tried recently.

(Obvious caveat being that any provider can trivially append @provid.er if you don't specify, so this isn't really proof that email is specified that way.)

eximius8y ago

Wow, that is literally the only reason I would want a TLD

fanf28y ago

ICANN forbids application records at the apex of a TLD. The only TLDs that do funky things like this are ccTLDs.

And if you try to actually use a bare TLD you will crash hard into collisions with unqualifed domains and search paths. So, fun as a hack to amuse fellow techies but not useful for anything real.

TremendousJudge8y ago

...is there someone out there who did this?

benchaney8y ago

Not that I'm aware of. Although I wouldn't be surprised if google did it for their employees. They already own the google TLD, they could very easily make it point to the google.com emails.

OJFord8y ago

How many HN-reading googlers have you just made to send 'Test' emails to themselves, I wonder!

eridius8y ago

Can you actually attach an MX record to a tld?

dj1yfk8y ago

https://gist.github.com/ddol/1445736

eridius8y ago

Huh, cool. Though I don't see a lot of those records myself. For example, `dig MX ai.` gives me the MX record for ai., but I can't see any MX records for as., bj., or dj.

marksomnian8y ago

.+@.+\..+

nradov8y ago

That regex is defective. See benchaney's reply above.

hfsktr8y ago

.+@.+(\..+)?

should satisfy you both right? I use the original or a form of usually when I had to check emails.

dasil0038y ago

That's identical to just doing .+@.+

simcop23878y ago

Fully qualified domains actually end in a . If you're allowing sally@google then you must also allow sally@google. To be valid

1 more reply

glandium8y ago

One (probably forgotten) reason people validated email addresses with convoluted regexps is that there are multiple (actually valid per RFC) email addresses formats that can do nasty things. Like explicitly specifying a series of mail servers to go through. They're (hopefully) deprecated and rejected by most servers nowadays, though.

snakeanus8y ago

> hopefully

Why?

contras19708y ago

> By default, this feature is turned off. This closes a nasty open relay loophole where a backup MX host can be tricked into forwarding junk mail to a primary MX host which then spams it out to the world.

http://www.postfix.org/postconf.5.html#allow_untrusted_routi...

sgustard8y ago

Thankfully my email is @@@@@@@.......

j / k navigate · click thread line to collapse

0 comments

vlunkr8y ago

I know lots of developers (myself included) who thought they could write a functional email regex. Eventually you learn that in the end, the way to validate an email address is to send an email.

OJFord8y ago

> Eventually you learn that in the end, the way to validate an email address is to send an email.

In my experience as a user, most people in the end also validate the email address by sending an email, but do no learning.

benchaney8y ago

Strictly speaking, the dot in the latter space isn't actually necessary. It needs to be a resolvable domain, but if you bought a TLD you could be "name@tld"

bitJericho8y ago

I don't think an @domain is required if it's an email address on the same mail server.

OJFord8y ago

That certainly used to work on Gmail; I haven't tried recently.

(Obvious caveat being that any provider can trivially append @provid.er if you don't specify, so this isn't really proof that email is specified that way.)

eximius8y ago

Wow, that is literally the only reason I would want a TLD

fanf28y ago

ICANN forbids application records at the apex of a TLD. The only TLDs that do funky things like this are ccTLDs.

And if you try to actually use a bare TLD you will crash hard into collisions with unqualifed domains and search paths. So, fun as a hack to amuse fellow techies but not useful for anything real.

TremendousJudge8y ago

...is there someone out there who did this?

benchaney8y ago

Not that I'm aware of. Although I wouldn't be surprised if google did it for their employees. They already own the google TLD, they could very easily make it point to the google.com emails.

OJFord8y ago

How many HN-reading googlers have you just made to send 'Test' emails to themselves, I wonder!

eridius8y ago

Can you actually attach an MX record to a tld?

dj1yfk8y ago

https://gist.github.com/ddol/1445736

eridius8y ago

Huh, cool. Though I don't see a lot of those records myself. For example, `dig MX ai.` gives me the MX record for ai., but I can't see any MX records for as., bj., or dj.

marksomnian8y ago

.+@.+\..+

nradov8y ago

That regex is defective. See benchaney's reply above.

hfsktr8y ago

.+@.+(\..+)?

should satisfy you both right? I use the original or a form of usually when I had to check emails.

dasil0038y ago

That's identical to just doing .+@.+

simcop23878y ago

Fully qualified domains actually end in a . If you're allowing sally@google then you must also allow sally@google. To be valid

1 more reply