3 ms·

just a few example emails that are listed as invalid but aren't "email with spaces"@gmail.com "very.unusual.@.unusual.com"@mail.yahoo.com "very.(),:;<>[]\".V

just a few example emails that are listed as invalid but aren't "email with spaces"@gmail.com "very.unusual.@.unusual.com"@mail.yahoo.com "very.(),:;<>[]\".VERY.\"very@\\ \"very\".unusual"@strange.example.com n@ai Another server-side alternative is isemail.info, which does validate all of the above.

aarondf 13y ago
Gah, TIL right? I had no idea those crazy examples were legit.
russjones 13y ago
Hi cleverjake, I'm the developer of this service at Mailgun. You can't actually register "email with spaces"@gmail.com or "very.unusual.@.unusual.com"@mail.yahoo.com with Google or Yahoo. Both addresses pass pure syntax checks but then the validator kills it when it notices that Google or Yahoo won't let you register addresses like that.
- Zikes 13y ago
  So it would be valid if I entered "very.unusual.@.unusual.com"@mail.zikes.me, assuming I created that address on my mailserver?
  - russjones 13y ago
    Hi Zikes, that's actually a bug, thanks for finding it. I'll fix it, and yes, that will soon be marked as valid.
- cleverjake 13y ago
  Hey russ, Yeah, I know you couldn't on gmail or yahoo, but I didn't know that you are using domain specific rules. Thats great!
graylights 13y ago
They're only valid if you can own that email address and The only one that looks valid there is the last n@ai, since apparently ai actually has an mx record. The first two are legal by rfc but not allowed by the individual providers. The third is not legit by rfc 2606 because example.com is a reserved domain. If it was just a RFC validation then it should validate all of those (except maybe example.com). But they go beyond that: "Furthermore, the validator is ESP specific, so we can go way beyond valid syntax checks, bring in specific requirement for Gmail vs. Yahoo vs. Hotmail."

3 ms·

just a few example emails that are listed as invalid but aren't "email with spaces"@gmail.com "very.unusual.@.unusual.com"@mail.yahoo.com "very.(),:;<>[]\".V

by cleverjake 13y ago

aarondf 13y ago
Gah, TIL right? I had no idea those crazy examples were legit.
russjones 13y ago
Hi cleverjake, I'm the developer of this service at Mailgun. You can't actually register "email with spaces"@gmail.com or "very.unusual.@.unusual.com"@mail.yahoo.com with Google or Yahoo. Both addresses pass pure syntax checks but then the validator kills it when it notices that Google or Yahoo won't let you register addresses like that.
- Zikes 13y ago
  So it would be valid if I entered "very.unusual.@.unusual.com"@mail.zikes.me, assuming I created that address on my mailserver?
  - russjones 13y ago
    Hi Zikes, that's actually a bug, thanks for finding it. I'll fix it, and yes, that will soon be marked as valid.
- cleverjake 13y ago
  Hey russ, Yeah, I know you couldn't on gmail or yahoo, but I didn't know that you are using domain specific rules. Thats great!
graylights 13y ago
They're only valid if you can own that email address and The only one that looks valid there is the last n@ai, since apparently ai actually has an mx record. The first two are legal by rfc but not allowed by the individual providers. The third is not legit by rfc 2606 because example.com is a reserved domain. If it was just a RFC validation then it should validate all of those (except maybe example.com). But they go beyond that: "Furthermore, the validator is ESP specific, so we can go way beyond valid syntax checks, bring in specific requirement for Gmail vs. Yahoo vs. Hotmail."