Provide more details. Like email address you tried in this test.

Comparing Standalone full-package scripts with other SaaS applications is not a good method. As those scripts don't provide you internal access you don't even know if they have a prebuilt database and gathering emails already to use in business. For example, your given testing email or provider already exists in their system and they do cross-check first with that before making an actual scan. Email Verifier Pro doesn't gather email addresses and has a small catch-all database. It allows the admin and user to add email address provider lists as they like.
For better accuracy, we have an option called Inbox Checker. Every setting we provide is customizable with Filter by Admin, Filters are configured with Regex. It just using different tastes of names, but that does not mean they are not using these also because you don't get to see their source code.