sendgrid.email.delivered: the delivered contract

Prove that the receiving server accepted the message. The delivered event of this message states it. It is the first event that a system outside Twilio SendGrid decides.

Contract identity.
Fact	Value
Contract id	`sendgrid.email.delivered`
Version	`1.0.0`
Hash	`23be0513771d3179`
Completion level	`delivered`
Publisher	Built and signed by Provely.
Certification	Provisional
Skill	Twilio SendGrid Mail API 0.1.0
Valid for provider API versions	`v3`

What is the intent?

Deliver the message to the mailbox of the recipient.

What is the subject and the action?

Member	Value
Subject type	`sendgrid.message`
Subject identity	provely_operation_id = `$action.result.provely_operation_id`
Canonical effect	`messaging.email_send`
Provider operation	`POST /v3/mail/send`
Idempotency	none, retry is not safe

How does the evidence correlate with this operation?

Strategy	Assurance	Keys	Required
`resource_id`	strong	provely_operation_id from `$action.result.provely_operation_id`	yes
`fingerprint`	weak	email from `$input.to`	no

Which evidence does the contract require?

Minimum evidence level E3. An independent channel is required. Minimum channels: 1.

Channel	Level	Independence	Verifier	Description
`processed_by_recipient`	E3	provider event	`webhook`	The processed events for this recipient since the operation started, whatever custom argument they carry. A count above one shows a second message. The verifier returns {events, count, latest, earliest, types, duplicates_dropped}.
`delivered_events`	E3	provider event	`webhook`	The delivered events that carry the custom argument of this operation. The receiving server accepted the message. The verifier returns {events, count, latest, earliest, types, duplicates_dropped}.
`processed_events`	E3	provider event	`webhook`	The processed events that carry the custom argument of this operation. Twilio SendGrid accepted the message and can deliver it. The verifier returns {events, count, latest, earliest, types, duplicates_dropped}.
`hard_bounce_events`	E3	provider event	`webhook`	The bounce events of this operation that state the type bounce. A hard bounce is a permanent denial. The match drops a block, which is a temporary denial. The verifier returns {events, count, latest, earliest, types, duplicates_dropped}.
`dropped_events`	E3	provider event	`webhook`	The dropped events of this operation. Twilio SendGrid dropped the message, and it never reached a receiving server. The verifier returns {events, count, latest, earliest, types, duplicates_dropped}.

Which conditions must all hold for VERIFIED?

Condition	Meaning	Path	Operator	Expected	Evidence
`delivered_event_present`	At least one delivered event of this operation arrived. The receiving server accepted the message.	`$observed.delivered_events.count`	`gte`	`1`	`delivered_events`
`delivered_event_present_in_window`	The provider clock of the earliest matched event is after the start of the operation. An older event belongs to another send.	`$observed.delivered_events.earliest.provider_timestamp`	`time_after`	`$operation.created_at`	`delivered_events`

Which conditions give CONTRADICTED?

Condition	Class	Reason	Path	Operator	Expected
`wrong_recipient`	wrong subject	The message went to a different recipient than the intent named.	`$observed.processed_events.latest.payload.email`	`ne`	`$input.to`
`message_predates_operation`	pre existing state	The earliest event of this message is older than the operation. It proves nothing.	`$observed.processed_events.earliest.provider_timestamp`	`time_before`	`$operation.created_at`
`duplicate_message_present`	duplicate side effect	Twilio SendGrid processed more than one message for this recipient since the operation started. Do not retry.	`$observed.processed_by_recipient.count`	`gt`	`1`

Which observed states map to a verdict before completion?

Rule	Match	Verdict	Reason
`message_bounced`	`$observed.hard_bounce_events.count` gte `1`	FAILED	The receiving server denied the message permanently.
`message_dropped`	`$observed.dropped_events.count` gte `1`	FAILED	Twilio SendGrid dropped the message. It never reached a receiving server.
`still_on_the_way`	(`$observed.processed_events.count` gte `1`) and (not (`$observed.dropped_events.count` gte `1`)) and (not (`$observed.delivered_events.count` gte `1`))	PENDING	Twilio SendGrid holds the message and no event states an end. The runtime observes again later.

How long does the runtime observe?

Timing member	Value
Initial delay	2000 ms
Poll interval	10000 ms
Backoff	exponential factor 2, max 300000 ms
Maximum attempts	60
Timeout	259200000 ms
Stale read window	30000 ms
On timeout	UNVERIFIABLE (`evidence_unavailable_before_timeout`), escalated to a person

Where do these rules come from?

sendgrid.openapi#/paths/~1v3~1mail~1send/post: sendgrid.openapi, retrieved 2026-09-08
sendgrid.docs.events#event-webhook/the-delivered-event/p1: sendgrid.docs.events, retrieved 2026-09-08
sendgrid.docs.events#event-webhook/deferrals/p1: sendgrid.docs.events, retrieved 2026-09-08
sendgrid.events#/events/delivered: sendgrid.events, retrieved 2026-09-08
sendgrid.docs.events#event-webhook/custom-arguments/p1: sendgrid.docs.events, retrieved 2026-09-08
sendgrid.docs.events#event-webhook/the-event-time/p1: sendgrid.docs.events, retrieved 2026-09-08
sendgrid.docs.events#event-webhook/the-properties-of-a-delivery-event/p1: sendgrid.docs.events, retrieved 2026-09-08

Can sendgrid.email.delivered return VERIFIED from the action response alone?

No. The minimum evidence level is E3. The action response is E1. The completion conditions read delivered_events.

What happens after the timeout?

The verdict is UNVERIFIABLE with the reason evidence_unavailable_before_timeout. The operation goes to a person for review.