Question

I need a regular expression that will accept well-formed emails in several formats (see below) that will be input in a comma-separated list. I have the basic email address
validation regex,

^[\w\d._%+-]+@(?:[\w\d-]+\.)+(\w{2,})(,|$) 

which can handle test cases A and B, but not the others. I also tried

^(\<)?[\w\d._%+-]+@(?:[\w\d-]+\.)+(\w{2,})(\>)?(,|$)

which was able to handle A, B, and C, but only validated the first email address in each of test cases D and E. I haven’t even gotten to testing a regex for format 3.

tl;dr Need a regex that will validate email addresses 1, 2, and 3.

Good website to test your regular expressions: Online Javascript Regex Tester

Data

Test Cases
A. [e-mail]
B. [e-mail], [e-mail]
C. <[e-mail]>, [e-mail]
D. <[e-mail]>, <[e-mail]>
E. [e-mail], <[e-mail]>

Email Address Formats
1. [e-mail]
2. <[e-mail]>
3. “xyz”<[e-mail]>

EDIT

I flagged this as a possible duplicate of:

Validate email address in JavaScript?

which, in turn, seems to be a duplicate of:

Using a regular expression to validate an email address

both of which contain much discussion on the validity of regex as email validation. However, the top-voted regexes provided don’t seem to do quite what I want so I don’t consider this answered yet.

Answer 1

None of the links or answers provided was the best answer for this question. Here’s what solved it:

/*
* regex checks: must start with the beginning of a word or a left caret
* must end with either the end of a word or a right caret
* can handle example.example.com as possible domain
* email username can have + - _ and .
* not case sensitive
*/
var EMAIL_REGEX = /(\<|^)[\w\d._%+-]+@(?:[\w\d-]+\.)+(\w{2,})(\>|$)/i;  
var emails = emailList.trim().split(',');  
var validEmails = [];  
var invalidEmails = [];  

for (var i = 0; i < emails.length; i++) {  
    var current = emails[i].trim();
    if(current !== "") {
        //if something matching the regex can be found in the string
        if(current.search(EMAIL_REGEX) !== -1) {
            //check if it has either a front or back bracket
            if(current.indexOf("<") > -1 || current.indexOf(">") > -1) {
                //if it has both, find the email address in the string
                if(current.indexOf("<") > -1 && current.indexOf(">") > -1) {
                    current = current.substr(current.indexOf("<")+1, current.indexOf(">")-current.indexOf("<") -1);
                } 
            } 
        }
        if(EMAIL_REGEX.test(current)) {
            validEmails.push(current);
        } else {
            invalidEmails.push(current);
        }
    }               
}