Ruby Email validation with regex

Question

I have a large list of emails I am running through. A lot of the emails have typos. I am trying to build a string that will check valid emails.

this is what I have

Answer 1

This one is more short and safe:

/\A[^@\s]+@[^@\s]+\z/

The regular is used in Devise gem. But it has some vulnerabilities for these values:

  ".....@a....",
  "david.gilbertson@SOME+THING-ODD!!.com",
  "a.b@example,com",
  "a.b@example,co.de"

I prefer to use regexp from the ruby library URI::MailTo::EMAIL_REGEXP

There is a gem for email validations

Email Validator

Answer 2

Nowadays Ruby provides an email validation regexp in its standard library. You can find it in the URI::MailTo module, it's URI::MailTo::EMAIL_REGEXP. In Ruby 2.4.1 it evaluates to

/\A[a-zA-Z0-9.!\#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*\z/

But I'd just use the constant itself.

Answer 3

TL;DR:

credit goes to @joshuahunter (below, upvote his answer). Included here so that people see it.

URI::MailTo::EMAIL_REGEXP

Old TL;DR

VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i

Original answer

You seem to be complicating things a lot, I would simply use:

VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z]+)*\.[a-z]+\z/i

which is taken from michael hartl's rails book

since this doesn't meet your dot requirement it can simply be ammended like so:

VALID_EMAIL_REGEX = /\A([\w+\-]\.?)+@[a-z\d\-]+(\.[a-z]+)*\.[a-z]+\z/i

As mentioned by CAustin, there are many other solutions.

EDIT:

it was pointed out by @installero that the original fails for subdomains with hyphens in them, this version will work (not sure why the character class was missing digits and hyphens in the first place).

VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i