Ruby: Remove "double dot" with regex [duplicate] - ruby

Question

This question already has answers here:
How can I validate an email address using a regular expression?
(79 answers)
Closed 9 years ago.
I'm using the following regex to validate emails in an email DB of a Rails App:
/\A[\w+\-.]+#[a-z\d\-.]+\.[a-z]+\z/i
it kinda works, but it leaves me with invalid mails wich have this kind of errors:
name#domain..com
How can I rwrite this regex to avoid that or wich is the best regex to clean up an email list I have to leave only valid email addresses? I'm using a method like this one to clean up the list:
def mailSweep
mails = Email.all.lazy
for address in mails do
if address.email.to_s =~ /\A[\w+\-.]+#[a-z\d\-.]+\.[a-z]+\z/i
puts address.email.to_s + " " + "it's valid"
else
puts address.email.to_s + " " + "it's invalid, destroying..."
address.destroy
end
end
end

Answer 1

I suggest
/\A[^#\s]+#([-a-zA-Z0-9]{1,63}\.)+[a-zA-Z0-9]{2,63}\z/
Note that this regex does not allow all legal email addresses. You need to something insanely complicated to allow for all RFC 822 valid email addresses that have been stripped of comments. If you want to include comments, then it is beyond the power of regular expressions and you have to go to a lexical parser.
Even then, you can't be sure the email is really valid. The best check is to try to send to it and see if the receiving system accepts it. Of course, even then it might be silently discarded....