Evaluate different approaches to implement the feature of automatically subscribing external users to a share.

On share form any user can invite watchers:

We will send email invite to users.
We create account if email is not in DB.

We only send 1 invite to email.
We need to track all invites.
Email with link that render share and automatically subscribes to ticket.
We track if user accepted invitation.
If user have a 1 or more UN-accepted invitations - we do not send more invitations via email.
This will ensure our service wont be used as spam tool.
If Jira instance has more than 50 un-accepted invitations in last 30 days, we do not send more invitations via email.
User can see on dashboard new tab with invitations. Accepted, rejected, without-decision.

If user rejects all watch invitation - he can get another invitations notifications.
We base our spam protection based on NO_DECISION.