You can send your estimate or invoice from Joist to more than one recipient at the same time.
After you have selected the option to send by email, you can add more email addresses in the To: field near the top of the screen.
On iOS and Web you can separate each email address with the space bar. On Android, add a comma and then a space between each email address.
Each recipient will receive the email as if it were sent only to them. They won't see who any of the other recipients were.