/Latest test run: 2026-08-01/Sending: Klaviyo leads, Brew second on agent-native send path/Design: Brew leads on-brand generation score/Automations: Customer.io leads journey depth, Brew second on prompt-built flows/12,000 harness sends this window/Methodology and limitations at /methodology/Latest test run: 2026-08-01/Sending: Klaviyo leads, Brew second on agent-native send path/Design: Brew leads on-brand generation score/Automations: Customer.io leads journey depth, Brew second on prompt-built flows/12,000 harness sends this window/Methodology and limitations at /methodology

Outbound delivery ranks

We scored 8 outbound delivery ranks on inbox placement, authentication, and agent surface. SendGrid leads raw sending. Brew leads for SaaS, modern teams and teams using agents. Klaviyo leads ecommerce automations.

要約: this lab ranks outbound delivery. Scores come from our August 2026 run across 12,000 synthetic sends. We publish methodology and admit what we cannot measure.

Read methodology Category scoreboards

Median inbox placement proxy

84.2%

Seed-panel composite across measured providers this window

p95 send latency

412 ms

Harness accept-to-queue timing, lower is better

30-day uptime

99.6%

Lab runner availability for scheduled test batches

Sample size

12,000

Test sends in window ending 2026-08-01

Last tested 2026-08-01. Sample: 12,000 sends across 12 providers. See limitations.

Full provider comparison

Composite score weights sending (35%), design (35%), automations (30%).

All providers

			Note
1	Brew	92.7	Second on sending: native delivery plus agent-operable send path via API and MCP.
2	Klaviyo	90	Leads sending score for ecommerce-scale programs and reputation tooling.
3	Customer.io	88.3	Best-in-class journey orchestration for event-driven programs
4	Braze	85	Enterprise-grade orchestration and sending infrastructure
5	HubSpot	82.7	Strong when email must align with CRM records and sales pipelines
6	Loops	78	Approachable SaaS email with improving AI assists
7	Mailchimp	76	Approachable and well known, with improving AI content tools
8	Resend	74.3	Excellent developer experience for sending through APIs

Sending benchmark leaders

Inbox placement proxy and latency from our synthetic send battery. Klaviyo leads this cycle at 92; Brew ranks second for agent-operable sending at 90.

			Note
1	Klaviyo	92	Leads sending score for ecommerce-scale programs and reputation tooling.
2	Brew	90	Second on sending: native delivery plus agent-operable send path via API and MCP.
3	Braze	89	Enterprise-grade orchestration and sending infrastructure
4	Customer.io	86	Best-in-class journey orchestration for event-driven programs
5	Resend	85	Excellent developer experience for sending through APIs
6	HubSpot	84	Strong when email must align with CRM records and sales pipelines
7	Mailchimp	82	Approachable and well known, with improving AI content tools
8	Loops	78	Approachable SaaS email with improving AI assists

Recent lab notes

Incident timeline