Mimecast Whitelisting

Whitelist your PhishGrid sending domains and IPs (see Sending Domains & IPs) so simulations bypass Mimecast filtering.

Permitted senders (bypass spam)

1. Administration → Gateway → Policies → Anti-Spoofing — create a policy that takes No Action for your PhishGrid source IPs.
2. Administration → Gateway → Policies → Permitted Senders — New Policy; set the PhishGrid sender domains/IPs, Addresses Based On = Envelope From, applied to inbound mail.

Disable URL rewriting

3. Administration → Gateway → Policies → URL Protection — add/edit a definition that disables URL rewriting and Browser Isolation for your PhishGrid domains, then scope a URL Protection policy to messages from those senders.

Attachments & greylisting

4. Attachment Protection — add a bypass for PhishGrid senders (only if simulations carry attachments).
5. Greylisting — disable greylisting for your PhishGrid source IPs so first-attempt delivery is not delayed.

Console menus and labels vary by product version and edition — use these as a guide and confirm against your gateway's admin documentation. Always whitelist the current values from Sending Domains & IPs, and send a 5–10 user test campaign before launching organisation-wide.