[Email Security] Fix Investigation cap

Author: Maddy-Cloudflare

src/content/docs/cloudflare-one/email-security/email-monitoring/search-email.mdx

@@ -192,7 +192,7 @@ With Email Security, you can export messages to a CSV file.
 To export messages:
 
 1. On the **Investigation** page, under **Your matching messages**, select **Export to CSV**.
-2. Select **Export messages** on the pop-up message. You can only export up to 1,000 rows from the dashboard. To export all matching messages, use the [API](/api/resources/email_security/subresources/investigate/methods/get/).
+2. Select **Export messages** on the pop-up message. You can only export up to 500 rows from the dashboard. To export all matching messages, use the [API](/api/resources/email_security/subresources/investigate/methods/get/).
 
 ## Email status