Cisco Spark vs mailboxlayer

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthapiKeyapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Cisco Spark vs mailboxlayer: common questions

Which is more reliable, Cisco Spark or mailboxlayer?

On our scheduled checks, mailboxlayer leads on measured uptime — Cisco Spark at —% versus mailboxlayer 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 Cisco Spark and mailboxlayer need an API key?

Both ask you to authenticate — Cisco Spark uses an API key and mailboxlayer uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.

Can I call Cisco Spark and mailboxlayer from the browser?

Only Cisco Spark is browser-friendly — it returns CORS headers over HTTPS. mailboxlayer needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Cisco Spark and mailboxlayer free for commercial use?

Cisco Spark has unclear commercial terms, and mailboxlayer 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.