Hello there,
I am a true master in PHP (and an eternal student). To be completely honest, I didn't know email verification providers and I thought it was a mission tu make sure an e-mail exists (not only that the format is valid), which I can do for sure. But after Googling (and finding "mailboxlayer" and "Trumail") I am still not too sure what they do but as I understood it, they just help you bounce e-mails from high reputation servers to make sure your e-mail is not served in the SPAM folder.
Anyway, if you have an API documentation and can explain me what is required, I can deliver top quality work. Please send me a message via chat for more clarifications.