Add option to notify appointment owners with ICS attachment or auto-add additional attendees

[woolfg]

I am using the Appointments app with a shared booking email address. The booking flow works well overall, but I ran into a problem when multiple people need to manage or see the booked appointments in their own calendars.

Current situation

When a user books an appointment, the booking user receives the confirmation email with the .ics file attached, assuming the setting “Attach .ics file to confirm/cancel emails” is enabled.

However, the owner/admin notification email, meaning the email that informs the appointment owner that a booking was confirmed, does not include an .ics attachment.

In my case, two people are responsible for the appointments. They use different personal calendars. The appointment is created in the calendar of the appointment owner, but the second person only receives or sees the owner notification email and cannot easily add the event to their own calendar.

Use case

A typical setup could look like this:

• A shared email address is used for appointment bookings, for example booking@example.com
• Two people are responsible for the bookings
• They use different calendars
• The appointment is created correctly in one calendar
• The booking user receives the .ics file
• The owner receives a notification email, but without .ics
• The second responsible person has no clean way to get the booking into their own calendar

Possible solutions

I see two possible ways to solve this:

Option 1: Attach the .ics file to the owner notification email

Add a setting so that the owner/admin notification email also includes the .ics file.

This could maybe reuse the existing .ics generation logic that is already used for the booking user confirmation email.

Possible setting name:

Attach .ics file to owner notification emails

This would make it easy to forward or process the owner notification email and allow other responsible people to manually import the event.

Option 2: Allow additional fixed attendees for all bookings

Add an option in the appointment configuration where the owner can specify one or more email addresses that should automatically be added as attendees to every booked appointment.

Example:

Additional attendees:
- person1@example.com
- person2@example.com

When a booking is created, these addresses would be added to the calendar event as attendees. Ideally, the calendar server would then send proper invitations/updates to them, so the events appear in their own calendars through the normal calendar invitation flow.

This might be the cleaner solution from a calendar perspective, because the additional people become real participants of the event instead of just receiving a copy of an .ics file.

Question

What do you think is the better approach?

I would be interested in contributing a PR for this, but before starting I would like to understand which solution you would prefer architecturally:

1. Add .ics attachments to owner notification emails
2. Add configurable additional attendees to every booking
3. Some other approach that fits the app better

Also, could you let me know what would be needed for such a PR to be mergeable? Anything I should consider?

Thanks for maintaining the app.