OpenSend docs
Email Tags
Tags are structured name/value labels attached at send time. Use tags to group related email activity by campaign, workflow, tenant, product area, or internal object ID.
Good tag patterns
campaign=welcomeworkflow=checkouttenant=acmesource=api
Tags should be stable and low-cardinality when they are used for reporting. Avoid putting raw user input or secrets in tag values.
Where tags help
Tags are most useful when support or operations needs to connect a dashboard email to the application event that created it. They complement idempotency keys: the idempotency key prevents duplicate acceptance, while tags help humans understand why a message exists.
Filtering logs and metrics by tag
Email tags can be used in the dashboard Logs and Metrics views.
- Logs accept tag name/value filters and return only request logs linked to emails with matching stored tags.
- Metrics accept tag name/value filters over the supported dashboard date presets: Today, Yesterday, Last 3 days, Last 7 days, Last 15 days, and Last 30 days.
- Metrics also show a bounded top-tag breakdown for the selected date range and tenant.
Tag filters are tenant-scoped and backed by bounded date ranges plus tag indexes. Keep reporting tags low-cardinality so dashboards remain fast.