Email regex

[sledorze]

When looking at existing solutions, it looks like it can be very complexe to properly validate en email address.

http://emailregex.com/

vs

https://github.com/hapijs/isemail/blob/master/lib/index.js

I think we should either provide a incomplete solution of link to existing io-ts based solutions out there.

What is the community thinking?

[steida]

I would use https://github.com/validatorjs/validator.js

[cogell]

Is there still an appetite for this? I could make a PR

[newswim]

@cogell I think it would be great if this library found a definition that satisfied the majority of use cases.