Guerrilla Mail vs PostStack
Same instrument, two spec sheets — measured, not claimed.
Guerrilla Mail vs PostStack: common questions
Which is more reliable, Guerrilla Mail or PostStack?
On our scheduled checks, PostStack leads on measured uptime — Guerrilla Mail at 95.1% versus PostStack at 100% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.
Which is faster, Guerrilla Mail or PostStack?
Guerrilla Mail has the lower median latency in our checks — Guerrilla Mail responds in 298 ms versus PostStack at 1066 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.
Do Guerrilla Mail and PostStack need an API key?
Guerrilla Mail needs no key, while PostStack requires a free API key. If you want to start calling without signup, reach for Guerrilla Mail first.
Can I call Guerrilla Mail and PostStack from the browser?
Only Guerrilla Mail is browser-friendly — it returns CORS headers over HTTPS. PostStack needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are Guerrilla Mail and PostStack free for commercial use?
Guerrilla Mail has unclear commercial terms, and PostStack 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.