Point your existing code at us — the /v3/mail/send payload you already send is accepted as-is. Bring your suppression list and templates with a read-only key, and you can be sending the same afternoon.
No credit card — 200 emails/day free for 100 days.
Swap the base URL and the token. Our /v3/mail/send compatibility endpoint accepts the payload you already build — no rewrite.
Paste a read-only API key from your old account. We import bounces, complaints, unsubscribes and blocks — the part that protects your reputation.
Handlebars renders as-is — {{#if}}, {{#each}}, {{this.x}} and friends. Anything outside that subset arrives as a draft, never published half-converted.
Domain reputation doesn’t transfer between providers, so this step is never automatic — anywhere. Verify your sending domain in Quathos Mailer (SPF, DKIM, DMARC), guided record by record, before your first live send.
Drop-in compatible
Your integration already builds this request. Point it here and keep going.
- https://api.sendgrid.com/v3/mail/send+ https://api.qsendyx.com/v3/mail/send - Authorization: Bearer SG.••••••••••••+ Authorization: Bearer qmx_live_••••••••Same 202 response, the same error envelope, the same header names. What we don’t honor field-by-field is rejected with a 4xx that says what to do instead — never accepted and silently dropped.
Field by field
Most of your payload just works. What doesn’t is rejected with a 4xx that tells you what to do instead — never accepted and ignored.
Honored
Rejected — with a reason
The same rule — 4xx over silent drop — applies to every field we don’t list here.
Before you switch
In most cases, no. Our /v3/mail/send compatibility endpoint accepts the payload you already build — same headers, same fields for what’s honored. Migrating is often just pointing the base URL and the token at us.
Your suppression list — bounces, complaints, unsubscribes, blocks — is exactly what protects the reputation you’re moving. Import it with a read-only key before your first live send, so day one doesn’t mean emailing everyone who already unsubscribed.
No — {{#if}}, {{#each}}, {{this.x}} and the common Handlebars constructs render as-is. Anything outside that subset imports as a draft with the reason, so nothing publishes half-converted.
Yes — domain authentication (SPF, DKIM, DMARC) is tied to reputation and doesn’t transfer between providers. It’s the one step that isn’t automatic, and it’s guided record by record in the dashboard.
Start free — 200 emails a day for 100 days. No credit card, no sales call.
Start migrating