API Keys allow you to generate an authentication credential that is separate from your username and password. They are independent from one another and are easily disposable. You should create unique API keys for each of your applications or servers so that you can easily revoke them without disrupting other systems if needed.
Sender Authentication is the functionality that shows ISPs that INBOXNotify has your permission to send emails on your behalf. This permission is given by the act of pointing very specific DNS entries from your domain registrar to INBOXNotify .
A common hurdle that many users encounter during the Sender Authentication process is that DNS records fail to validate, even though the records were just created! Firstly, you can check our DNS records with your records what you added.
There are numerous reasons why email providers place messages into the Spam folder. While there is no surefire way to ensure your messages arrive into the inbox of your recipients, there are however industry standards and best practices you can follow to give your emails the best chance of meeting all mail provider and spam filter expectations.