After 2,100 emails bounced from one campaign, I built my own verification API. Live on PH today.

A few months ago I ran a campaign to ~14,000 emails I'd collected through legitimate signups. 2,100 bounced. Our sender reputation tanked, mailbox providers throttled the next three sends, and the

open-rate cohort took a quarter to recover.

The infuriating part: most of those addresses looked fine. Valid format. MX records present. A free verifier had marked them deliverable.

Turns out most email verifiers stop at the easy checks. Format and MX get you ~60% of the way. The remaining 40% disposable inboxes (Mailinator etc.), role addresses, typo'd domains (gmial.com),

catch-alls that accept everything and bounce later is where deliverability actually dies.

So I built Trumailo. It runs all eight signals format, MX, real SMTP RCPT-TO handshake to the recipient's server, catch-all probe with a canary local-part, role detection, 30k-domain disposable

list, provider mapping, Levenshtein typo suggestions in a sub-100ms JSON response. Cached responses under 10ms.

What's different:

- Real RCPT probe, not just MX lookup same handshake your customer's MTA does

- Catch-all detection via canary RCPT, not "we accept everything" guessing

- Full stack is open source Go API, Next.js dashboard, Postgres/Redis/NATS. Self-host or use our cloud.

- WordPress plugin just got approved by WP.org (auto-detects 20 form / CRM / checkout plugins)

- $0.38 / 1k on the Pro plan vs $5.24 industry average. 7-day unlimited trial. Free during beta 200/month, no card.

Live on PH right now → trumailo.com

Would genuinely love feedback. What checks are we missing? What integrations should I ship next? Anything that would make this a "yes, immediately" tool for you?