To filter by Subject, you can create a Gmail filter ,by clicking here:https://mail.google.com/mail/u/0/?shva=1#settings/filters
1. Click create a new filter” and enter a unique term (for whatever your actual unique subject term is) into the Subject text field
2. Click “ Create filter with this search”
3. Check off “Star it” and click “Create filter”
SaneBox interprets a “Star” to mean “leave it in my Inbox forever” regardless of it’s age or importance. If you Star an email in your @SaneLater, we will automatically move that email to your Inbox as well. This is how the “ Once” button in your email digest is mechanized.