It checks so many then it breaks down with:
550 SC-001 (COL004-MC4F20) Unfortunately, messages from 126.96.36.199 weren’t sent. Please contact y
There should be some gap between requests. if you’re verifying too many emails too frequently for a single mail server, then obviously it’s going to be blacklisted.
This looks like API server/network in New York was blocked/blacklisted. Any one to confirm? Is there a way to fix it, or we should look for other API?