Google Workspace gives Gmail administrators several ways to manage incoming email received by their organization. You can block specific senders using a denylist, and bypass spam filters with an allowlist or an approved senders list.
Email allowlist—A list of IP addresses you define as approved to send mail to your domain. If you notice that legitimate messages from specific contacts are incorrectly marked as spam, you can allowlist the contact's IP address. After you allowlist an IP address, messages that come from that IP address won't be put in the spam label. However, users who receive email from that IP address are likely to still see a Gmail warning banner on those messages (for example, This email looks suspicious). For more information, visit Add IP addresses to allowlists in Gmail.
Email denylist—A list of email addresses you block from sending mail to your organization or domain. Admins can block domains or specific users with the Blocked senders setting. Additionally, users can create a filter in their mailboxes to automatically send messages from specific users or email lists to the Trash. Your users should also report unwanted messages as spam. This helps Gmail's spam filters identify future spam messages. For more information, visit Manage unwanted messages in Gmail.
Approved senders list—Approved senders are trusted users that send email to your organization. Create an address list of approved senders so messages from these users bypass Gmail’s spam filters, and recipients can decide whether they are spam or not. Create the list with individual email addresses, or by adding an entire domain. For more information, visit Customize spam filter settings in Google Workspace.