Context

• node version: 5.11.1
• joi version: 8.4.2
• environment (node, browser): Node
• used with (hapi, standalone, ...): Hapi
• any other relevant information:

What are you trying to achieve or the steps to reproduce ?

1. Attempt to validate a utf-8 email address such as: jØrgen@somedomain.com
2. Get 'invalid' validation result

Note that this email is considered invalid, which is correct, but permitted by https://tools.ietf.org/html/rfc6530

const schema = Joi.string().email()

Which result you had ?

Email address was marked as invalid. This is a problem as I would now have to use a regexp or simple string validation for email addresses which significantly reduces readability.

What did you expect ?

I'd hope for some method of switching between RFC versions - perhaps by passing in the rfc number. I don't really have any other 'good solutions' for this.

Google, for example support sending and recieving from RFC 6530 emails, but not signing up with them - they would use something like:

const signupSchema = Joi.string().email({compliance: 'rfc5322'})
const sendingSchema = Joi.string().email({compliance: 'rfc6530'})

Of course compliance could be changed to international: true/false' or something similar, but I think compliance is more explicit.