How to match a comma separated list of emails with regex?

Question

Trying to validate a comma-separated email list in the textbox with asp:RegularExpressionValidator, see below:

Answer 1

The following RegEx will work even with some of the weirdest emails out there, and it supports a comma between emails.

((?:[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-zA-Z0-9-]*[a-zA-Z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\]),?)+

A few Examples:

Valid: planetearth@solar.com
Valid: planet.earth@solar.com
Valid: planet.earth@solar.com,blue.planet@solar.com
Valid: planet-earth@solar-system.com,/#!$%&'*+-/=?^_`{}|~@solar.org,"!#$%&'-/=^_`{}|~.a"@solar.org
Invalid: planet earth@solar.com

Hope This helps.