An SMTP and API gateway built for deliverability: verified domain identities, progressively warmed IP pools, full event tracking — without running your own sending infrastructure.
Access is granted on request — accounts are provisioned manually to protect every domain's sending quality.
The building blocks expected of a professional sending infrastructure, in a single gateway.
Progressive, tiered ramp-up on fresh dedicated IPs, with automatic pausing if bounces or complaints exceed the threshold.
Real-time HTTPS notifications (send, delivery, bounce, complaint) signed with HMAC-SHA256, with automatic retries on failure.
Hard bounces and complaints automatically removed from future sends, per client, with CSV import/export.
Your mail goes out from IP addresses that are never shared with other clients, organized into pools by warm-up stage.
One key per client, revocable at any time, usable as an SMTP password or an API token.
Domain ownership proof, RSA 2048 DKIM, SPF and DMARC verified before any sending is enabled.
Add the ownership TXT record, then the DKIM and SPF records generated for you.
A single key, usable as your SMTP password or as an API token.
Over SMTP (587/465) or via the API, at the quota and rate matched to your warm-up stage.
Events, bounces, complaints and reputation, live, in your client portal.
No proprietary SDK required — it works with anything that speaks SMTP.
# auth: your API key doubles as your SMTP password curl --url 'smtp://smtp.zenoses.com:587' --ssl-reqd \ --mail-from 'you@yourdomain.com' \ --mail-rcpt 'recipient@example.com' \ --user 'you@yourdomain.com:zk_your_api_key' \ -T message.eml
Accounts are opened manually — write to us and we'll take a look at your case.
Request access