The one time I had to validate email addresses without using another library, I settled on /.+@.+\..+/ Basically the same as yours, but validate that a TLD exi

The one time I had to validate email addresses without using another library, I settled on /.+@.+\..+/ Basically the same as yours, but validate that a TLD exists. Technically, this would fail on a few valid email addresses: foo@localhost, foo@.co, or foo@2001:0db8:85a3:0000:0000:8a2e:0370:7334 All those are valid, but we decided that none of those would apply to any of our customers.