Some corporate and organization email systems may filter out Event Farm emails, due to settings within the company's or organization's email system settings. When this happens, emails are not delivered to the user's inbox, nor the user's junk or spam mailbox.
If the Guest List shows both a Last Action and Last Notified statuses, but the user is not receiving the email to their work or private email domain (this excludes popular consumer email systems, like Gmail, Hotmail, Yahoo, and iCloud), there is a good chance the email is being caught by an email system filter.
Check with the company's IT team or email administrator, and ask if they have received, blocked, or quarantined emails from Event Farm. To ensure future Event Farm emails are delivered to a user's inbox, have them whitelist the following IP addresses and domains: