SMTP Labs

Web · API · paid plans from $7/mo

Freedom report

Two barsScore 6.4

Free tierA free tier is on its own pricing page
Open codeNo open-source code on record
Runs widely1 of 6 device platforms
DocumentedPlans, terms and facts published

SMTP Labs is ranked #8 of 28 in email testing software on Freedom251. It runs on API, Web. There is a free plan. Paid plans start at $7/mo.

SMTP Labs plans and pricing

All plans

Lite Free 1 domain · 50 accounts · Messages kept for 7 days · SMTP, IMAP, POP3, API · Email audit smtp.dev · 3 Oct 2026

Pro $7/mo 5 domains · 25,000 accounts · Messages kept for 30 days · SMTP, IMAP, POP3, API · Email audit · Catch-all & aliasing smtp.dev · 3 Oct 2026

Max $20/mo Unlimited domains · Unlimited accounts · Messages kept for 90 days · SMTP, IMAP, POP3, API · Email audit · Catch-all & aliasing smtp.dev · 3 Oct 2026

Compared on email testing software

Free plan: Yes
Paid from: $7/mo
Spam checks: Yes
Link checks: Yes
Inbox testing: Yes
API access: Yes

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The record

Purpose: SMTP Labs is an email testing service that receives test email over SMTP and lets users inspect it through the web UI, IMAP, POP3, or API.
Sandbox: The service receives real email but sends only within its sandbox, so test messages cannot reach external recipients.
Protocols: The product supports SMTP, IMAP, and POP3 without requiring a vendor SDK.
Message inspection: Users can inspect HTML and plain text, headers, MIME structure, raw source, and attachments.
Authentication checks: SPF, DKIM, and DMARC checks are shown in the UI and available through the API.
Deliverability audit: The deliverability audit reviews sender configuration, HTML structure, links, and content patterns spam filters flag, grouped by severity.
API and realtime: The REST API covers domains, accounts, mailboxes, messages, and tokens; new messages can be pushed through server-sent events.
Integrations: The maker documents CI use with GitHub Actions, Jenkins, GitLab CI, and CircleCI, using standard SMTP and the REST API.
Domains and aliases: Users can bring custom domains and subdomains, use catch-all accounts, and route plus-sign aliases.
Retention: Message retention depends on the plan and can be up to 90 days, with shorter per-message expiry available.
Security and email data: The privacy policy says it uses encryption, firewalls, and SSL technology, and does not use email content for advertising or unrelated purposes.
Data location: The privacy policy says email content and account information are primarily stored and processed in the United States.
Account deletion: Users can request account deactivation, but full account deletion is unavailable because of anti-abuse obligations.
Support: The terms state the company has no support or maintenance obligation except as may be included in a paid subscription plan.
Price from: $7/mo

Where it ranks on Freedom251

Best Email Testing Software in 2026#8 of 28

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Sources

smtp.dev· checked 3 Oct 2026
smtp.dev/docs/guides/ci/· checked 3 Oct 2026
smtp.dev/docs/getting-started/· checked 3 Oct 2026
smtp.dev/legal/privacy/· checked 3 Oct 2026
smtp.dev/legal/terms/· checked 3 Oct 2026
smtp.dev/pricing/· checked 3 Oct 2026