shipapis
StarSubmit an APISubmit API

caldays vs mail.tm

Same instrument, two spec sheets — measured, not claimed.

APIcaldaysNEW—mail.tmNEW—
Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms——
P95 · ms——
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — temporary mailboxes
Rate limitUnpublishedRate limited (429 on exceed); exact policy per docs.mail.tm
In directory since2026-07-052026-07-05
operationalpartialdownno data

caldays vs mail.tm: common questions

Which is more reliable, caldays or mail.tm?

On our scheduled checks, mail.tm leads on measured uptime — caldays at —% versus mail.tm at —% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Do caldays and mail.tm need an API key?

Neither needs a paid key — caldays is callable with no signup, and mail.tm is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call caldays and mail.tm from the browser?

Yes — both caldays and mail.tm send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.

Are caldays and mail.tm free for commercial use?

caldays has unclear commercial terms, and mail.tm has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.