Manage email block and allow rules

Control unwanted or trusted email at the address or inbound-domain level. Choose the communication direction deliberately and inspect overlapping rules before changing a B2B customer or supplier’s mail flow. An allow rule affects trust handling but does not override a conflicting block.

Before you begin

• Identify the exact sender or recipient address, the message direction and the observed problem. Separate blocked inbound mail, blocked outbound mail and spam/phishing trust handling.
• Inspect existing full-address and @domain rules. A broad supplier-domain block can affect legitimate messages from many Contacts.
• Plan an approved test message with a safe address and known route. A saved rule is configuration evidence; it is not proof that a particular message was delivered.

Configure and verify

1. Open Settings → Email configuration → Block/Allow list. Search for the complete address and its @domain form, then use Refresh to inspect current rules.
2. Open a matching rule or choose New rule. Enter the complete email address or domain form such as @example.com.
3. Choose Policy for the actual purpose. Block inbound controls incoming mail; Block outbound requires a specific full address. Domain rules apply to inbound mail.
4. Use Allow sender for trusted-sender spam/phishing handling only when appropriate. First inspect overlapping address/domain blocks because an allow entry does not override them.
5. Add a Reason explaining the incident, intended scope and review context for another administrator. Save and confirm the rule in the refreshed list.
6. Test the intended direction through the approved test route. Inspect the observed result and any relevant email-routing evidence before concluding the issue is resolved.
7. Before Delete, understand why the rule exists and what mail behavior will become possible. Remove only the intended rule after confirmation, then repeat the relevant controlled check.

Settings reference

Rule fields and actions

Recommended use

• Start with the narrowest address scope that solves the problem. Use a whole-domain inbound rule only when all senders in that domain should be affected.
• Use reasons that explain the operational decision and review context. Avoid unexplained permanent exceptions that another administrator cannot assess.
• Keep inbound, outbound and trusted-sender tests separate. Passing one test does not establish the behavior of the other direction.

Worked example

1. One sender at a supplier sends unwanted messages to the support address. The administrator confirms the full sender address and checks both address and domain rules.
2. They choose a narrow inbound block for that sender rather than excluding all supplier Contacts.
3. They verify the saved rule and use an approved controlled message to check the intended route.
4. Later, a legitimate supplier sender remains blocked despite an allow entry. The administrator inspects the overlapping domain block instead of creating repeated allow rules or broadening the exception without review.

Troubleshooting

Related configuration

• Email configuration → Configure inbound email routes
• Email configuration → Configure an outgoing SMTP connector