Our opt-in has code to test for valid email addresses.
However, a.) it hangs / it's slow and b.) sometimes it rejects *valid* email addresses.
Can you fix it and still get the job done (validate email by pinging the mailbox, not just checking for proper syntax).
For your information, we've attached a.) the code and files as-is and b.) alternative code we paid for but didn't integrate that you can use if it works.
Include your bid + expected turn-around time with your response.