[BE-32] Email campaigns to member segments: backend

[yusuftomilola]

Overview

Admins have no way to send targeted marketing or informational email campaigns beyond one-off notifications. Email campaigns enable member engagement, re-activation outreach, and event promotion at scale.

Context

• EmailModule: backend/src/email/
• User entity with membershipStatus, isVerified, role for audience segmentation
• BullModule already configured for async job queuing — use it to batch-send without blocking

Tasks

• Create EmailCampaign entity: id, subject, bodyHtml (text), targetSegment (ALL / ACTIVE / INACTIVE / STAFF), scheduledAt (nullable timestamptz), sentAt (nullable), status (DRAFT / SCHEDULED / SENDING / SENT), recipientCount (int, set after send), createdByAdminId (FK), createdAt
• POST /email-campaigns — create campaign as DRAFT (admin only)
• PATCH /email-campaigns/:id — edit draft (admin only; reject if status !== DRAFT)
• POST /email-campaigns/:id/send — enqueue send job immediately (status → SENDING) or set scheduledAt (status → SCHEDULED)
• Bull worker job: resolves target users by segment, sends email to each via EmailModule, increments recipientCount, sets status = SENT and sentAt
• GET /email-campaigns — paginated list (admin only) with status filter
• GET /email-campaigns/:id — campaign detail (admin only)

Files to Modify / Create

• New: backend/src/email-campaigns/ (module, entity, controller, service, bull processor)
• backend/src/app.module.ts

[Oluwasuyi-Timilehin]

@Oluwasuyi-Timilehin has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello, I’m a full stack developer with hands-on experience building with variety of tools including Nextjs, nodejs, nestjs, React, Typescript and more
I focus on writing clear, maintainable code and making sure features work as expected end to end, not just in isolation. I communicate progress regularly and keep things transparent as I work. I’m confident I can complete this task within an ETA of 4 HOURS

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Oluwasuyi-Timilehin to this issue.

[NteinPrecious]

@NteinPrecious has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

can i please be assigned to this?

ℹ️ Repo Maintainers: To accept this application, review their application or assign @NteinPrecious to this issue.

[ghost-cy829]

@ghost-cy829 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I would like to work on this issue. I have experience with Rust and Soroban smart contract development. I will follow the acceptance criteria and add tests. Excited to contribute. Kindly assign.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ghost-cy829 to this issue.

[drips-wave]

Congratulations, @NteinPrecious! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @NteinPrecious: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[grantfox-oss]

🦊 GrantFox — @NteinPrecious has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #1211)
2. Your PR will be reviewed by the DistinctCodes maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@NteinPrecious's PR #1256 was approved and merged by @yusuftomilola.

🏆 @NteinPrecious: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (681 total points). Track your full progress on GrantFox.

👏 Great work, @NteinPrecious! Keep contributing to DistinctCodes.

[drips-wave]

This issue has been completed by @NteinPrecious as part of the Stellar Wave Program's 6th Wave 🥳

😎 @NteinPrecious: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.