useSend Integration for Mailbase
The main integration page for hosted Mailbase sending and BYO useSend workflows.
Overview
Mailbase is built for people who want a clearer workflow around email sending and replies. Hosted plans use Mailbase-managed sending after you verify a sender domain. The bring-your-own useSend plan connects your useSend API URL, API key, default sender, and webhook secret so Mailbase can send and ingest delivery or reply events through your stack.
This page is intentionally transparent: hosted plans use Mailbase-managed sending, while the BYO useSend plan keeps the sending/infrastructure side under your control.
The best audience is technical: indie hackers, SaaS founders, Coolify users, Railway users, VPS owners, and developers who are already comfortable with domains and deliverability.
Who This Is For
This integration is for people who are comfortable owning part of their email stack: a VPS, Docker deployment, Coolify service, Railway deployment, or hosted/self-hosted useSend instance. Hosted Mailbase plans are the better fit when you want the workflow without operating useSend yourself.
The strongest BYO fit is a builder who wants to keep infrastructure control while making the day-to-day workflow easier to reason about.
- Developers and indie hackers
- SaaS founders with a server
- Coolify and Railway users
- Technical marketers working with engineering
- Teams exploring useSend or AWS SES
Requirements
Before connecting anything, prepare the infrastructure basics. Do not skip domain authentication just because a dashboard looks ready.
- For hosted plans: a verified sender domain in Mailbase
- For BYO: a server/VPS, Coolify service, Railway deployment, or hosted useSend instance
- For BYO: useSend deployed and configured
- For BYO: enter your useSend API URL, API key, default sender, and webhook secret into Mailbase
- A sending domain with SPF, DKIM, and DMARC reviewed
Setup Steps
- Choose hosted Mailbase sending or BYO useSend.
- For BYO, prepare useSend using the official docs.
- Open Mailbase settings and choose the useSend connection.
- Connect credentials: input your useSend API URL, API key, default sender, and webhook secret.
- Test the connection to ensure Mailbase can query useSend status.
- Start managing workflows: compose A/B campaigns and reply to thread messages.
Why Connect useSend to Mailbase
The point is not to hide the infrastructure. The point is to keep control of it while giving yourself a clearer operating layer.
- Keep infrastructure control
- Avoid unnecessary vendor lock-in
- Stay close to a developer-friendly setup
- Use the €5/month bring-your-own useSend plan when you run your own delivery
- Get the workflow layer — inbox, campaigns, A/B tests, MCP — without paying for sending you already operate
Common Mistakes
- Choosing a tool before deciding who owns deliverability.
- Treating DNS authentication as a one-time checkbox instead of an operating baseline.
- Mixing product-critical transactional email with experimental marketing sends, with no clear boundary.
- Trusting headline metrics (like open rate) that privacy proxies now inflate.
Sources & Further Reading
Official docs for current setup details, pricing, and API behavior — verify specifics there, since they change.
Related guides
More on usesend integration and the surrounding integrations workflow:
FAQ
What do I need before connecting useSend?
Only the BYO plan needs a useSend instance. For that path you'll prepare a running useSend deployment, a sending domain, and four credentials to paste into Mailbase: API URL, API key, default from address, and webhook secret. Hosted plans skip all of this — verify a sender domain in Mailbase and you're sending.
Does Mailbase host useSend?
Hosted plans use Mailbase-managed sending on shared platform infrastructure. BYO useSend is separate: you run the delivery stack and connect it to Mailbase.
Is the integration free?
You can start on the free plan, then use the €5/month bring-your-own useSend plan when you want the full Mailbase workflow layer on your own delivery stack.
Can I use Mailbase without my own useSend instance?
Yes. Hosted plans use Mailbase-managed sending after sender-domain verification. The BYO useSend plan is for teams that already run or want to run their own delivery stack.