Digests
When emails are fetched from your email provider, we first classify the email. You can see this type of labeling at work in Gmail; their defaults included social, updates, forums, and promotions. We’ve extended the concept in order to gain precise control over presentation.
Digests are a single summary, of all unread emails of a single category. The purpose of this feature is to enable you to catch up on messages quickly in case you fall behind. If you mark this item as read or delete, then all of the messages used as source for the digest will have their associated summaries marked the same. By default, digests will be added to your Instack every day at 8am and 8pm UTC.