Add a trigger for newsletter delivered webhook

[naz]

blocked by https://www.notion.so/ghost/Email-DB-Structure-03454f8ae3ec4044a8b018a7b9808276

Problem

Following Zapier flow needs support:

When a newsletter is successfully delivered ⇒ send a notification to Slack saying "post.title was successfully delivered to [members.total] members"

Technical solution

Add a trigger subscribed to a Ghost event which happens once newsletter is sent out. At the moment it's in early development stages and would need to track progress of changes related to this spec.

References

Notion discussion - https://www.notion.so/ghost/Email-delivery-status-webhook-72faf173d1c5430397bbe1b834a86bbd

[naz]

@royalfig I'm closing this issue for now, as it has been stale for over 2 years. But it might be a good one to revisit once you start looking for features to implement in Zapier. Also, a good summary of what might be enabled next is the flow we didn't get to implementing during this audit - https://www.notion.so/ghost/Audit-Zapier-Integration-Ghost-7b02756d1f3d43dc8ae68d70640b43c4