Helo is an email API built for developers and platforms that send on behalf of their customers. Contain bad senders before they drag down deliverability, let customers send from their own domains, and keep stats, unsubscribes, and credentials separate per tenant. It also covers the fundamentals: REST API and SMTP, SDKs in popular languages, separate transactional and broadcast infrastructure, and usage-based pricing starting at just $0.00035 per email—all features included.
Hi PH! I'm Bettina, one of the humans behind Helo, an email API for sending transactional and marketing email from your application: password resets, receipts, notifications, newsletters, etc.
Most of our team worked together at Postmark for many years, so we know what it takes to build a rock-solid email service. If you've ever loved a product and then watched it get acquired, you probably know the rest of that story. We started Helo to keep building the kind of product we're good at, improve on what we have learned, take good care of our customers, and stay independent while doing it. We're bootstrapped and plan to stay that way.
Helo covers everything you'd expect from a developer-focused email service:
- REST API and SMTP, with SDKs for Ruby, JS, C#, Python and Go (more to come) - Separate infrastructure for transactional and broadcast mail (so we can optimize deliverability for both) - Event logs, stats, webhooks, suppressions, unsubscribes, flexible permissions - Fair, usage-based pricing with no arbitrary feature gates - https://www.helohq.com/pricing
Beyond that, we designed Helo to fully support multi-tenant sending.
Most email providers are built for the general case: a single company sending its own emails to its own customers. But what if you build a platform that sends on behalf of your customers? Let’s say you’re building a restaurant management tool and want your restaurant owners to be able to send newsletters from your platform. You suddenly face a whole new set of spicy challenges. If one of your customers is sending spam, how do you catch that and ensure that one bad sender doesn’t spoil deliverability for your entire product? How can you make it easy for your users to send from their own domains? How can you make sure that recipients that unsubscribe from restaurant A’s newsletters are still receiving mail from restaurant B? The list goes on.
We've built Helo to address all of these concerns, while also allowing flexibility in how the relationships between domains, webhooks, credentials, etc. are defined amongst your tenants.
If you've built multi-tenant sending before, what was most painful? Is there something you wish your email provider handled for you but doesn't? I'd love to hear about it.
And, of course, I'd also love it if you gave Helo a try. 🧡
the bootstrapped-and-staying-independent line hits different after watching postmark get acquired. on the per-tenant isolation - is that dedicated IPs per customer, or shared pools with reputation scoring per sender? asking because shared-pool is way cheaper to run but one bad tenant can still drag the whole pool down in practice, even with good internal tracking.
About Helo on Product Hunt
“An independent email API from former Postmark folks”
Helo launched on Product Hunt on October 1st, 2026 and earned 75 upvotes and 3 comments, placing #20 on the daily leaderboard. Helo is an email API built for developers and platforms that send on behalf of their customers. Contain bad senders before they drag down deliverability, let customers send from their own domains, and keep stats, unsubscribes, and credentials separate per tenant. It also covers the fundamentals: REST API and SMTP, SDKs in popular languages, separate transactional and broadcast infrastructure, and usage-based pricing starting at just $0.00035 per email—all features included.
Helo was featured in Email (36.8k followers), API (98.7k followers) and Developer Tools (520.4k followers) on Product Hunt. Together, these topics include over 105.9k products, making this a competitive space to launch in.
Who hunted Helo?
Helo was hunted by Bettina Specht. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how Helo stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Hi PH!
I'm Bettina, one of the humans behind Helo, an email API for sending transactional and marketing email from your application: password resets, receipts, notifications, newsletters, etc.
Most of our team worked together at Postmark for many years, so we know what it takes to build a rock-solid email service. If you've ever loved a product and then watched it get acquired, you probably know the rest of that story. We started Helo to keep building the kind of product we're good at, improve on what we have learned, take good care of our customers, and stay independent while doing it. We're bootstrapped and plan to stay that way.
Helo covers everything you'd expect from a developer-focused email service:
- REST API and SMTP, with SDKs for Ruby, JS, C#, Python and Go (more to come)
- Separate infrastructure for transactional and broadcast mail (so we can optimize deliverability for both)
- Event logs, stats, webhooks, suppressions, unsubscribes, flexible permissions
- Fair, usage-based pricing with no arbitrary feature gates - https://www.helohq.com/pricing
Beyond that, we designed Helo to fully support multi-tenant sending.
Most email providers are built for the general case: a single company sending its own emails to its own customers. But what if you build a platform that sends on behalf of your customers? Let’s say you’re building a restaurant management tool and want your restaurant owners to be able to send newsletters from your platform. You suddenly face a whole new set of spicy challenges. If one of your customers is sending spam, how do you catch that and ensure that one bad sender doesn’t spoil deliverability for your entire product? How can you make it easy for your users to send from their own domains? How can you make sure that recipients that unsubscribe from restaurant A’s newsletters are still receiving mail from restaurant B? The list goes on.
We've built Helo to address all of these concerns, while also allowing flexibility in how the relationships between domains, webhooks, credentials, etc. are defined amongst your tenants.
If you've built multi-tenant sending before, what was most painful? Is there something you wish your email provider handled for you but doesn't? I'd love to hear about it.
And, of course, I'd also love it if you gave Helo a try. 🧡