client side email validations uses a list of known domains.
look for the following code:
var knownDomsPat = /^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/i;
you can add other domains to this list for email validation to pass them:
var knownDomsPat = /^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum|cat)$/i;