Sending Emails via REST API Not Sending

I’ve been trying to send test emails via the API to ensure it works and I get the Accepted 202 status and it shows on the activity board on the dashboard but no emails were sent. I updated my email to send from my yahoo and gmail but nothing.

Here’s my data that I send

  "html_content": "PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8Ym9keT4KCjxoMT5NeSBGaXJzdCBIZWFkaW5nPC9oMT4KCjxwPk15IGZpcnN0IHBhcmFncmFwaC48L3A+Cgo8L2JvZHk+CjwvaHRtbD4KCg==",
  "subject": "Test Email via API",
  "plain_content": "TXkgRmlyc3QgSGVhZGluZwpNeSBmaXJzdCBwYXJhZ3JhcGgu",
  "contacts": [
  "user_id": 1

Has the email address for contactId #3 been opt-in? What is it’s current status? When you navigate to the contact within the UI, are you seeing the email in the email history?