Attach Files to Emails with Lightning Knowledge
Use the Insert Article to Email Action in Lightning Experience to attach Knowledge article files from the related list. Choose which attachments to include by removing those you don’t need from the email. You can send files larger than your org’s email attachment limits as a link.
Where: This change applies to Lightning Experience in Essentials, Developer, and Unlimited editions. Salesforce Knowledge is available for an additional cost in Professional, Performance, and Enterprise editions.