That doesn't work for instances where a person/company is using a subdomain (such as www.site.archive.com – would not be accurate for .ar [Argentina]), as well as individual's email addresses (such as suzy.millison@site.com – would not be accurate for .mil [military]). Thusly why it would have to be "ends with"
But then you catch partial matches in the local part of the email address (the username), like john.ukman@example.comas well as domain matches like sandy@example.uk.net. You can try to narrow in with other conditions but you'll never be totally accurate.
What I sometimes do is parse out the domain as a whole (using a webhook) into private domain + public domain (2LD/TLD) fields.
The addition of an [ends with] constraint would save a lot of webhook pain!