CoreCubes makes mobility, expense, and time-registration processes as simple as possible for organisations running AFAS as their HR and payroll system. Its SaaS application connects directly to AFAS: employees register trips, expenses, and hours in a purpose-built environment, and approved data flows back into AFAS automatically. Alongside the SaaS product, CoreCubes builds custom applications for its customers.
Many of its customers are healthcare organisations, municipalities, and other public institutions with strict requirements around data processing. CoreCubes is ISO 27001 certified itself, and runs a supplier procedure with an explicit preference for European vendors.
The problem
Email started out as a side concern for CoreCubes, but that changed as the team built more applications that genuinely depend on it: magic-link logins, support mailboxes feeding a portal, notifications from custom-built apps. Meanwhile, sovereignty kept climbing the agenda. The company had already moved its own workspace from Microsoft to Proton, and in security reviews and tenders, customers increasingly ask where data lives, where it is processed, and which subprocessors CoreCubes itself relies on.
Their email provider at the time was Resend: good to work with, quick to start, but American. Other European alternatives they tried were, in their words, so bureaucratic that they spent more time talking to support than sending email.
Why AhaSend
Three things mattered: deliverability, a European and sovereign platform, and the ability to connect multiple applications quickly. "We found all three at AhaSend," says Koen Freriks, owner of CoreCubes. "And the pricing is sharp, so we can scale along as volume grows."
The sovereignty argument pays off directly in sales conversations with the public sector. "In security reviews and tenders we're asked where data is processed and which subprocessors we use. Being able to name a European supplier for email saves us discussion in that process. We see it becoming a hard criterion more and more."
Migration and results
The migration was refreshingly small: reconfigure domains and DNS, swap the API calls. "We converted six applications within one hour," Freriks says.
Since then, email has stopped being a project line item. "We now set up an email integration within minutes, live on the domain we want. Everything we need, from transactional mail and magic links to inbound email via routing rules, is simple to configure. For a new custom application, email is no longer a separate part of the project."
Delivery is not a nice-to-have in that setup. Logging into CoreCubes' applications works with magic links: if the email does not arrive, the user simply cannot log in. And the support portal runs on AhaSend's inbound routing: incoming emails are delivered straight into the application via the API. "An email that doesn't arrive is a support question we never see."
One line from the interview we did not expect: "The documentation is so clear that the AI models we develop with understand it immediately. That's how we get an email integration for a new application running within half an hour."
What stood out
Two things surprised the CoreCubes team.
First, the routing feature. "Routing worked far more simply than expected," Freriks says. "For our support portal, emails arrive in a mailbox and are pushed straight into the application via the API. Setting that up took considerably less time than I had estimated. It saved us real headaches building the portal."
Second, the support. "I recently ran into a small bug, and it was fixed the same evening."
Would CoreCubes recommend AhaSend?
"Wholeheartedly. With the free tier you can implement a solution and keep it in production immediately. Once you scale, the pricing is attractive, and you can trust that things are well arranged. For other Dutch SaaS builders, including those in the AFAS ecosystem, that's a pleasant combination: start fast without running into your own choice later."
At a glance
- Six applications migrated from Resend to AhaSend within one hour
- Magic-link logins and a support portal that depend directly on email delivery
- Inbound email routed straight into their support application via the API
- New email integrations live within minutes; no longer a separate project component
- A European supplier to name in public-sector security reviews and tenders
- ISO 27001-certified customer with an explicit European supplier preference
Building applications that depend on email? Put them on the same infrastructure CoreCubes relies on.