Do all valid emails contain at least one @ symbol?

Question

I'm not trying to come up with full email validation. I'm trying to prevent a specific problem:

I've had users use the contact form on my website, which asks for "Name", "Email" and "Message", and just by hilarious mistake, I get the info, "First Name", "Last Name", "Message", and I think to myself, 'Shit where did I leave my Yellow Pages?'

So, I don't want to validate email, I just want to remind people that it's not last name we're asking for it's email.

I'm thinking I check for an @ symbol, and I want to make sure I'm not neglecting valid emails.

Are there valid emails with no @ symbols in them?

Answer 1

As per RFC5322:

An addr-spec is a specific Internet identifier that contains a locally interpreted string followed by the at-sign character ("@", ASCII value 64) followed by an Internet domain.

So, yes, all email addresses must have the @ character.

Prior to the internet taking over the world, it was possible for email addresses to have other formats, like the FidoNet mail address 1:170/918.10, user number 10 at FidoNet node 1:170/918.

But given the ratio of internet users to FidoNet users currently stands at about a gazillion or more to one, that's for historical interest only.

Answer 2

As defined in RFC5322, section 3.4.1:

An addr-spec is a specific Internet identifier that contains a locally interpreted string followed by the at-sign character ("@", ASCII value 64) followed by an Internet domain.

https://www.rfc-editor.org/rfc/rfc5322