On the Free plan, only 3 share link emails can be sent each hour. If you reach that limit, you may encounter an error message that we are unable to send your email. You will need to wait approximately 1 hour before sending any more share links via email.
If you regularly need to send more than 3 share link emails per hour, you can upgrade to a paid plan. With a paid plan, there is no limit to the number of email invites that can be sent.
Note: This limiting only applies when the owner of the prototype is on the Free plan. If you are a Free user who is a member of a Team plan, and you create a prototype on the Team plan, there's no limit to how many email invites can be sent for that prototype.