no issue
We want to store a list of recipients for each bulk email so that we have a consistent set of data that background processing/sending jobs can work from without worrying about moving large data sets around or member data changing mid-send.
- `email_batches` table acts as a join table with status for email<->email_recipient
- stores a provider-specific ID that we get back when submitting a batch for sending to the bulk email provider
- `status` allows for batch-specific status updates and picking up where we left off when submitting batches if needed
- explicitly tying a list of email recipients to a batch allows for partial retries
- `email_recipients` table acts as a join table for email<->member
- `member_id` does not have a foreign key constraint because members can be deleted but does have an index so that we can efficiently query which emails a member has received
- stores static copies of the member info present at the time of sending an email for consistency in background jobs and auditing/historical data
