MailSenpai DNS Check
Check a domain's SPF, DKIM, DMARC and MX records and get what to fix, with the values to publish

Email API and SMTP for sending transactional and bulk emails, with email testing sandbox for safe development.
Mailtrap API is a free Email API that requires apiKey authentication, is served over HTTPS and has unconfirmed CORS support.
Modern Email Delivery Platform for developer & product teams. Fast delivery. High inboxing rates. 24/7 expert support. Email API/SMTP for reliable email sending
Details from mailtrap.io.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Check a domain's SPF, DKIM, DMARC and MX records and get what to fix, with the values to publish
Verify email deliverability with a strict yes/no, disposable and catch-all detection
EU-hosted email API for transactional and marketing email, with contacts, broadcasts, and analytics
Disposable inboxes for end-to-end signup tests, with long-polling and HMAC-signed webhooks
The Mailtrap API is provided by Mailtrap (mailtrap.io). Modern Email Delivery Platform for developer & product teams. Fast delivery. High inboxing rates. 24/7 expert support. Email API/SMTP for reliable email sending
Yes. The Mailtrap API is listed in the Email category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Mailtrap API uses apiKey authentication, so you need to register for credentials before making requests.
CORS support for the Mailtrap API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Mailtrap API is served over HTTPS, so it's safe to use in production.