Email load testing workflow with real inbox assertions

Test email delivery under load with real inboxes

Provision disposable inbox cohorts during stress runs, wait for matching emails, and prove signup, password reset, magic link, notification, and campaign workflows still deliver when traffic spikes.

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Create isolated inboxes for every worker, shard, or scenario

Generate inbox pools during k6, JMeter, Locust, Playwright, Cypress, and custom harness runs. Keep concurrent users isolated so receipt timing, content, and routing stay measurable.

TSload-test.ts

// Define an inbox-scoped deliverability test with explicit inbox targets and a minimum-count expectation.
const createdTest = await deliverabilityTestController.createDeliverabilityTest({
  createDeliverabilityTestOptions: {
    name: `deliverability-test-${Date.now()}`,
    description: 'admin-sdk deliverability progression test',
    scope: 'INBOX',
    selector: {
      type: 'EXPLICIT',
      entityIds: [inboxA.id!, inboxB.id!]
    },
    expectations: [
      {
        name: 'expect-1-each',
        minCount: 1
      }
    ],
    maxDurationSeconds: 300
  }
});
deliverabilityTestId = createdTest.id;

MailSlurp (examples)

const matchingEmails = await mailslurp.waitForMatchingEmails(
  {
    // match for emails with no attachments
    conditions: [
      {
        condition: ConditionOptionConditionEnum.HAS_ATTACHMENTS,
        value: ConditionOptionValueEnum.FALSE,
      },
    ],
    // match for emails from a specific email address
    matches: [
      {
        field: MatchOptionFieldEnum.FROM,
        should: MatchOptionShouldEnum.CONTAIN,
        value: inbox.emailAddress,
      },
    ],
  },
  1,
  inbox.id,
  timeout,
  unreadOnly
);

Measure real message arrival instead of queue success

Wait for matching emails, inspect links and codes, compare latency, and keep delivered-message evidence for high-traffic releases, provider migrations, and campaign launches.

MailSlurp (examples)

const matchingEmails = await mailslurp.waitForMatchingEmails(
  {
    // match for emails with no attachments
    conditions: [
      {
        condition: ConditionOptionConditionEnum.HAS_ATTACHMENTS,
        value: ConditionOptionValueEnum.FALSE,
      },
    ],
    // match for emails from a specific email address
    matches: [
      {
        field: MatchOptionFieldEnum.FROM,
        should: MatchOptionShouldEnum.CONTAIN,
        value: inbox.emailAddress,
      },
    ],
  },
  1,
  inbox.id,
  timeout,
  unreadOnly
);

Integrate MailSlurp Seamlessly

Integrate with any framework

Official plugins and SDKs for all major programming languages, frameworks, and test platforms. All functionality available via API or dashboard.

CI/CD Native

MailSlurp fits right into your existing development, testing, and CI/CD workflows. Deploy and iterate with confidence and actionable feedback.

Developer Integrations

Built for load-sensitive email workflows

Add real inbox evidence to performance runs so QA and engineering teams can catch delivery, timing, and content regressions before customers do.

Inbox pools on demand

Create disposable inboxes per virtual user, test shard, tenant, region, or scenario so high-concurrency checks stay isolated.

Deterministic wait APIs

Wait for matching emails by sender, subject, body, attachment state, unread state, and timeout from test code or HTTP calls.

Latency and content checks

Capture arrival timing, message headers, links, OTP codes, attachments, and payload metadata while traffic is increasing.

Framework-friendly HTTP APIs

Use REST APIs and official SDKs from k6, JMeter, Locust, Playwright, Cypress, CI jobs, or internal performance harnesses.

Release-ready artifacts

Keep inbox-backed run data for launch reviews, incident analysis, provider migrations, and high-volume notification changes.

Email and SMS coverage

Combine inboxes with phone numbers when signup, MFA, OTP, password reset, or notification paths cross both channels.

Email load testing with real message evidence

Emails processed

500 million+

Infrastructure for high-volume message workflows.

Test frameworks

SDKs

Use APIs from load tools, CI jobs, and custom harnesses.

Inbox creation

On demand

Create isolated addresses for runs, workers, and scenarios.