The white label email API
built for platforms like yours.
Building a CRM, helpdesk, invoicing tool, or anything that sends email as your customers? Ark is the email platform built specifically for that. Integrate once, manage every customer domain from one place, and get back to building your actual product.
7-day free trial. No credit card needed.
127
243
12,847
98.39%
inbox delivery rate
Thousands
of domains managed
$29/mo
to get started
Other email tools weren't built for this
Resend, Postmark, SES - they're built for companies sending their own emails. You're not doing that. You're sending on behalf of hundreds of customers, each with their own domain.
Try doing that with a single-sender tool and you'll spend weeks building tenant isolation, domain management, and debugging dashboards on top of their API. Ark is the only email platform where multi-tenant is the default, not an afterthought.
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Purpose-built for platforms
CRMs · Helpdesks · Invoicing · Scheduling · Live chat
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Every customer, isolated
Domains · Logs · Analytics · Debugging - per customer
See exactly what's happening, per customer
“Customer #204 says their emails aren't arriving.” With other tools, good luck finding that needle. With Ark, every customer is isolated - their own domain, their own logs, their own analytics. Search, filter, and debug across your entire customer base from one dashboard.
New customer domain? Two minutes, zero support tickets.
When your customer adds their domain, Ark detects their DNS provider - Cloudflare, GoDaddy, Route53, you name it - and shows them the exact steps. Some providers, we configure it automatically. No Zoom calls to explain what a TXT record is.
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Auto-detect & configure DNS
Cloudflare · GoDaddy · Route53 · Vercel · Namecheap
Teams that stopped building email infrastructure
"We spent three weeks trying to make SES work for multi-tenant. Switched to Ark and had 50 customer domains sending in an afternoon. Wish we'd found it sooner."
Marcus R.
CTO at a scheduling platform
"We used to dread onboarding new customers because of the domain setup. Now it's self-service. Our support team literally forgot it used to be a problem."
Sarah K.
Head of Product at a CRM
"Finally an email API that understands we have customers, not just one sender. The per-customer isolation alone saved us months of building."
James L.
Lead Engineer at an invoicing tool
Plans that grow with your customer base
Start at $29/mo with 10 domains and 50K emails. Scale to 1,000 domains when you need to. Unlimited team members on every plan.
See pricing detailsWhite label email that your customers actually want
Your customers don't want emails coming from your domain. They want their brand on every message. Invoices from [email protected], not from yours. That's what white label email gives them. And that's what makes your platform feel like a real part of their business, not a bolt-on tool.
The problem is that no other email API is built for this. Resend, Postmark, SendGrid, SES: they all assume one company, one domain. Try to add a second customer domain and you're already writing custom code. Try to add a thousand and you're building an entire email platform on top of theirs. SPF records, DKIM keys, DMARC policies, domain verification flows, per-customer logs. It adds up fast.
Ark is the email API where all of that is built in. Add a new customer, connect their domain, and they're sending authenticated email in minutes. Every customer gets their own domain, their own sending logs, their own deliverability stats. You can see exactly who's sending what, debug a single customer's emails without digging through a shared log, and manage thousands of domains from one dashboard.
Because Ark is purpose-built for platforms, you also get everything you'd eventually need to build yourself: webhooks per tenant, suppression lists per customer, email activity APIs so you can surface sending data inside your own product. It's white label email infrastructure that lets you ship email as a feature, not spend six months becoming an email company.
You're building a product,
not an email platform.
Let us handle that part.
Start your 7-day free trial. No credit card needed.