CASE STUDY · TELECOM & MESSAGING
White-label email marketing & delivery platform
We designed and built a complete email sending platform for a business messaging provider, so it could offer email campaigns and transactional email to its own clients under its brand, with resellers managing their client books and credit.
3role levels: clients, admins and super admins
4services across Node.js and Java
53screens across three portals
26data models behind campaigns, contacts and reporting
THE CHALLENGE
What needed to happen
The provider already sold messaging services to businesses and wanted to add email to its portfolio. That meant much more than a mail form: clients needed to design and send campaigns, manage contacts, verify their own sending domains and plug email into their applications. Admins needed to onboard clients and allocate sending credit, and the provider needed platform-wide control, reporting and an architecture that could absorb large sends and a steady stream of delivery events.
WHAT WE DELIVERED
From drag-and-drop design
to delivery analytics.
Client portal
- Create, edit, test and send email campaigns
- Contact groups with individual and bulk file imports
- Import history with job status tracking
- Per-campaign analytics for delivery, opens, clicks and bounces
- Link-level click-through breakdowns
- Dashboard, MIS and per-recipient delivery log reports
Drag-and-drop template builder
- Visual editor that produces responsive email HTML
- Reusable templates for campaigns and transactional mail
- File attachments stored securely with pre-signed links
- Test sends before a campaign goes live
Developer sending channels
- Single and bulk transactional send APIs with API-key authentication
- API key rotation and an in-app developer documentation page
- An embedded SMTP server with per-client credentials
- Works with any standard mail client or library
- Sender domain registration with SPF and DKIM DNS records
- Domain verification checks, suppression lists and blocked domains
Reseller & admin hierarchy
- Admins onboard and manage their own book of clients
- Super admins manage admins and every client platform-wide
- Sending credit issued down the hierarchy with full recharge history
- Deactivate and reactivate accounts at every level
- Secure “log in as” impersonation for support
- Reports scoped automatically to each role
Sending & event pipeline
- A worker service that dispatches campaign and transactional sends
- A receiver service that ingests delivery, bounce, open and click events
- Click-tracking redirects feeding link analytics
- Message queues with retry handling between services
Storage & infrastructure
- Self-hosted S3-compatible object storage for files and imports
- Containerised services with a private image registry
- Platform-wide system settings managed from the super-admin portal
ENGINEERING & OPERATIONS
- Separate, JWT-secured route trees for clients, admins and super admins
- Redis-backed job queues for bulk imports and campaign processing
- RabbitMQ messaging between the API and the Java sending and event services
- Asynchronous event ingestion so analytics keep up with high-volume sends
- Pre-signed upload and download URLs so files never pass through the API
- Swagger documentation for the full API
- Docker images for every service, published to a private registry
- A documented QA test plan covering every role
WHAT IT MADE POSSIBLE
- A new email product line the provider can sell under its own brand
- Resellers able to onboard clients and manage credit without the provider’s help
- Clients sending through a visual builder, a REST API or plain SMTP
- Clear delivery, engagement and credit reporting at every level
- An architecture that separates sending and event processing so each can scale
TECHNOLOGY
Tools we used
ReactTypeScriptViteTailwind CSSTanStack QueryGrapesJSMJMLNode.jsExpressPrismaPostgreSQLRedisRabbitMQJavaSpring BootSMTPS3-compatible storageDockerSwagger
Client name and confidential details withheld.MORE WORK
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