Using KnowBe4.com to send your users simulated phishing and training emails?
KnowBe4.com.
knowbe4.com or the related sub-domains (e.g. psm.knowbe4.com)
knowbe4.com mail host (or sub-host, such as psm.knowbe4.com).
knowbe4.com, phisher.knowbe4.com or kb4.io
knowbe4.com mail host and will therefore be subject to normal filtering.
knowbe4.com staff sends mail through external services, such as Outlook or Gmail, those messages are subject to normal filtering. Generally, that should not be a problem as simulated phishing emails won't come from those sources. You can optionally add knowbe4.com as an Approved Sender if you choose.