Invite Teammate
Send this when someone invites a colleague to their workspace. It names the person who sent the invite and the workspace, puts the Accept invite button up front, and says when the invite expires. Pass the inviter's name, workspace name and invite link as data, and make sure the link works for someone who has no account yet.
Loops
Make the sender recognizable
Pass the inviter's name, workspace name, invite URL and expiry as required transactional data. Use the inviter's real name, since the recipient may not know your product yet. Test an expired or already used link so it lands on a page that explains what to do next, and keep marketing content out until the new user has signed up. The welcome examples cover what to send once they join.