Whitelisting is extremely important for conducting a phishing simulation test successfully. It would prevent the phishing security test emails from being blocked or filtered into the spam folder.
We recommend that you whitelist the emPower IP address in your mail server if you're not using a cloud-based spam filter. If you are using a cloud-based spam filter, you will need to whitelist by email header in your mail server and whitelist by IP address in your spam filter.
The steps that need to be taken will vary across different email clients, servers, and internet security platforms. Take into consideration the various products or services you may be using in your mail or web environment to prevent issues with deliverability. Here are some articles to help you with whitelisting:
Exchange 2013, 2016, & Office 365: