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SMTP Labs

APIyesOSS—FREEyesDOCS5/5
SL7.3#7 of 28
outWeb—Windows—Mac—Linux—Android—iOS

Ranked in Email Testing Software ·Free plan· paid from $7/mo

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About

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

Compared on email testing software

Free plan
Yessmtp.dev
Paid from
$7/mosmtp.dev
Spam checks
Yessmtp.dev
Link checks
Yessmtp.dev
Inbox testing
Yessmtp.dev
API access
Yessmtp.dev

Facts

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.smtp.dev · 3 Oct 2026
Sandbox
The service receives real email but sends only within its sandbox, so test messages cannot reach external recipients.smtp.dev · 3 Oct 2026
Protocols
The product supports SMTP, IMAP, and POP3 without requiring a vendor SDK.smtp.dev · 3 Oct 2026
Message inspection
Users can inspect HTML and plain text, headers, MIME structure, raw source, and attachments.smtp.dev · 3 Oct 2026
Authentication checks
SPF, DKIM, and DMARC checks are shown in the UI and available through the API.smtp.dev · 3 Oct 2026
Deliverability audit
The deliverability audit reviews sender configuration, HTML structure, links, and content patterns spam filters flag, grouped by severity.smtp.dev · 3 Oct 2026
API and realtime
The REST API covers domains, accounts, mailboxes, messages, and tokens; new messages can be pushed through server-sent events.smtp.dev · 3 Oct 2026
Integrations
The maker documents CI use with GitHub Actions, Jenkins, GitLab CI, and CircleCI, using standard SMTP and the REST API.smtp.dev · 3 Oct 2026
Domains and aliases
Users can bring custom domains and subdomains, use catch-all accounts, and route plus-sign aliases.smtp.dev · 3 Oct 2026
Retention
Message retention depends on the plan and can be up to 90 days, with shorter per-message expiry available.smtp.dev · 3 Oct 2026
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.smtp.dev · 3 Oct 2026
Data location
The privacy policy says email content and account information are primarily stored and processed in the United States.smtp.dev · 3 Oct 2026
Account deletion
Users can request account deactivation, but full account deletion is unavailable because of anti-abuse obligations.smtp.dev · 3 Oct 2026
Support
The terms state the company has no support or maintenance obligation except as may be included in a paid subscription plan.smtp.dev · 3 Oct 2026

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Where it ranks on Inferse

Sources