Use Posts at Scale to Reach Multiple Members at Once
Where: This feature is available in Lightning communities, accessed through Lightning Experience and Salesforce Classic. Communities are available in Enterprise, Performance, Unlimited, and Developer editions.
How: Click the Select All checkbox at the top of your report. If you have more than 500 members in your results, only the first 500 are selected to keep performance at a maximum. After completing the post, rerun the report, and repeat the bulk post operation.