The request names MailTester, so MailTester.com comes first: it verifies single or batched email addresses and tests deliverability before sending 111. Alternatives for email testing and sending include MailSlurp for programmable inboxes and inbox-placement tests 2, Mailtrap for sandbox sending and test inboxes 4, and Resend for sending transactional email with delivery status checks 515.
- 1
MailTester.commailtester.comverified and signed
Verifies single addresses and batches of up to 25 per call, returning valid, invalid, risky or unknown verdicts so you can clean lists before sending 11.
official:MCP server · MailTester Email Verification
for agents: Verify one email address · Verify a small batch
- 2
MailSlurpmailslurp.comverified and signed
Creates programmable inboxes and tests email and SMS flows through APIs, SDKs and SMTP, including inbox placement checks 2.
for agents: test · email · smtp
- 3
Mailtrapmailtrap.iofound in code, not yet checked
Sends emails in a sandbox test inbox without delivering to real recipients, with spam report details 4.
+1 community tools built for it
for agents: send-sandbox-email · show-sandbox-email-message · send-email
- 4
Resendresend.comverified and signed
Sends text or HTML email via API and retrieves each sent email's delivery status 15.
+12 community tools built for it
for agents: send_email · get_email_status · GET /emails/{email_id}
Sources
- 1MailTester.com — Email Verifier & Deliverability Testmailtester.com · read 2026-10-29
- 2Email and SMS testing, email quality and automation | MailSlurpmailslurp.com · read 2026-10-29
- 4Documentation | Mailtrap Help Centerdocs.mailtrap.io · read 2026-10-29
- 5Resend · Email for developersresend.com · read 2026-10-29
- 11MailTester: declares "Verify one email address" (the record we read and signed)unfragile.ai · read 2026-10-24
- 15Resend (Activepieces): declares "send_email" (the record we read and signed)unfragile.ai · read 2026-10-24
For agents: the 10 actions behind this answer
Verify one email address · MailTester verified and signed
Returns valid, invalid, risky or unknown for a single address. e.g. Is jane.doe@example.com a real mailbox?
test · mailslurp-client verified and signed
· fixture.email website read, tools not yet checked
Spin up real inboxes, send and receive actual email, and assert on it in your end-to-end tests — an AI-native alternative to Mailosaur your AI coding agent can wire up on its own.
send-sandbox-email · MCP Mailtrap Server found in code, not yet checked
Send an email in sandbox mode to a test inbox without delivering to your recipients
send_email · Resend (Activepieces) verified and signed
Send Email — Send a text or HTML email
· mailfixture website read, tools not yet checked
Create a real test inbox in one API call. Your app sends the OTP. We hand it to your test — parsed, typed, and on time.
· ZeroDrop website read, tools not yet checked
Verify OTPs and magic links from code. Real disposable inboxes caught at Cloudflare's edge — auto-extracted email.otp and email.magicLink. No Docker, no regex, no signup.
· Webmailagent website read, tools not yet checked
Create temporary inboxes for AI agents and QA. Wait for verification emails, extract OTP codes and magic links, and clean up every test run through REST or MCP.
testEndpoint · primitive.dev verified and signed
Send a sample email.received event to a webhook endpoint to verify your signature verifier. Rate limited to 4/min and 30/hr. Successful deliveries and verified-domain endpoints are exempt.
· Fabricatedemail website read, tools not yet checked
An HTTP API that gives your tests disposable email addresses and the mail that arrives at them. Built for CI, not for browsing.
Labels are the instruments' verdict and are never changed by ranking. Agents and robots get this same answer as JSON at /api/v1/find?q=…&answer=1 and through the MCP server.