tweaked description of 50K mailbox limit

Author: markjjo

exchange/exchange-ps/exchange/policy-and-compliance-content-search/New-ComplianceSearchAction.md

@@ -438,7 +438,9 @@ The Purge switch specifies the action for the content search is to remove items
 
 Notes:
 
-- A maximum of 10 items per mailbox can be removed at one time and a maximum of 50,000 mailboxes will searched. Because the capability to search for and remove messages is intended to be an incident-response tool, this limit helps ensure that messages are quickly removed from mailboxes. This action isn't intended to clean up user mailboxes.
+- A maximum of 10 items per mailbox can be removed at one time. Because the capability to search for and remove messages is intended to be an incident-response tool, this limit helps ensure that messages are quickly removed from mailboxes. This action isn't intended to clean up user mailboxes.
+
+- You can remove items from a maximum of 50,000 mailboxes using a single content search. To remove items from more than 50,000 mailboxes, you'll have to create separate content searches. For more information, see Search for and delete email messages in your Office 365 organization (https://docs.microsoft.com/office365/securitycompliance/search-for-and-delete-messages-in-your-organization).
 
 - Unindexed items aren't removed from mailboxes when you use this switch.