Shareable URLs
By default, any email you create on your own workspace is private, and viewable only by you.
You can share emails with teammates to work collaboratively by adding their email address in the Share menu in the upper right corner.
Plan
The number of users you can share an email with depends on your plan.
You can share your email publicly by accessing the Share menu in the upper right corner, changing Private to Public and then clicking Copy Link. Anyone with the link can view your email but will not be able to collaborate with you directly.