hii ,Sunila Sheth

go you domain model and add validation rule on Email Address Attribute

Select commuity commons Email Address RegExp 

and click ok 

after that you can check 

it will work 

hope it will help you

Hi Sunila Sheth,

For which attribute you need to use regex. Go to the domain model → Validation rule tab click new and add the attribute and you need to map the rule type as Regular expression.

Added the screenshot for reference.