Decision Tool - Is Regex - failure

Morning everyone,

Context: Business is looking at saving messaging cost, by sending an email instead of an sms - as it works out cheaper. In the business we do however face a concern with regards to the correctness of the email addresses captured by agents. We are now looking at reporting on incorrectly captured contact details in an attempt to increase the success rates of contacting our customers.  

Approach: We looked at using the decision tool's Is Regex functionality, with regular expression /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/ to validate an email.

Problem: We found that the functionality is not working as expected - when entering a valid email address the validation fails instead of passing.

I have attached a sample workflow to demonstrate the concern: EmailValidation.bite