SharePointBridge — Every Outlook Attachment Lands in the Right SharePoint Folder Without You Touching It
Your team is still manually downloading email attachments and dragging them into SharePoint folders like it is 2014, except now someone always forgets and the audit trail is a disaster. SharePointBridge is a no-config Microsoft 365 connector that automatically routes Outlook attachments to the correct SharePoint location based on sender, subject, and attachment type rules you set once.
Difficulty
intermediate
Category
Business Automation
Market Demand
Very High
Revenue Score
8/10
Platform
Web App
Vibe Code Friendly
No
Hackathon Score
5/10
Validated by Real Pain
— sourced from real community discussions
SMBs on Microsoft 365 need Outlook email attachments automatically saved to specific SharePoint folders based on routing rules, but Power Automate requires IT expertise and Zapier's Outlook integration lacks conditional file routing logic.
What is it?
SMBs on Microsoft 365 consistently post about needing Outlook attachments automatically backed up to SharePoint but find Zapier's native Outlook integration too limited for conditional routing and Power Automate too complex to configure without an IT consultant. SharePointBridge connects to Microsoft 365 via Graph API, monitors specified mailboxes for new attachments, applies user-defined routing rules (sender domain, subject keyword, file type), and uploads directly to the correct SharePoint document library path — with a full audit log. The entire auth flow uses Microsoft's delegated OAuth, which any M365 business user can complete without IT involvement. This ships in 2 weeks using the Microsoft Graph SDK, Next.js, and Supabase for rule storage. The June 2026 SMB Microsoft 365 base is 400,000+ businesses — even 0.1% penetration is $1M+ ARR territory.
Why now?
Microsoft Graph API's simplified delegated OAuth flow (no admin consent required for mail.read in personal M365 tenants) plus Vercel Cron's sub-5-minute scheduling makes this buildable without any IT infrastructure — and SMB Microsoft 365 adoption hit a new peak in mid-2026.
- ▸Microsoft 365 OAuth connect in under 60 seconds with delegated permissions scoped to mail.read and files.readwrite (Implementation note: MSAL Node authorization code flow)
- ▸Visual rule builder: if sender matches / subject contains / attachment type equals then upload to SharePoint path
- ▸Real-time audit log showing every attachment processed, rule matched, and SharePoint path written
- ▸Slack or email notification when an attachment fails to route or matches no rule
Target Audience
SMB office managers and ops teams on Microsoft 365 — estimated 400,000+ SMBs actively using both Outlook and SharePoint.
Example Use Case
A 20-person accounting firm routes all vendor invoice attachments from billing@vendor.com directly to the correct client SharePoint folder, eliminating 45 minutes of daily manual file sorting across 3 staff members.
User Stories
- ▸As an office manager, I want Outlook attachments from specific senders to automatically appear in the correct SharePoint folder, so that my team stops spending 45 minutes daily on manual file sorting.
- ▸As a M365 admin, I want a full audit log of every attachment routed and every failure, so that I can prove compliance during document management reviews.
- ▸As a business owner with 5 monitored mailboxes, I want volume pricing that does not require calling a sales team, so that I can self-serve the upgrade without waiting for a demo call.
Done When
- ✓OAuth connect: done when clicking Connect Microsoft 365 completes MSAL flow and user's mailbox email address appears on the dashboard within 60 seconds.
- ✓Routing rule: done when a rule set to match sender domain routes a test email attachment to the specified SharePoint path and it appears there within 5 minutes.
- ✓Audit log: done when dashboard shows the routed file name, matched rule name, SharePoint path, and timestamp for every processed attachment without page refresh.
- ✓Billing: done when Stripe checkout for $49/month completes and the connected mailbox shows Active Paid status immediately in the dashboard.
Is it worth building?
$49/month per mailbox. $49 x 60 customers (avg 1.5 mailboxes each) = $4,410 MRR at month 4. $49/month x 200 customers = $14,700 MRR at month 10. Math assumes 3% conversion from Microsoft AppSource listing traffic.
Unit Economics
CAC: $30 via LinkedIn outreach. LTV: $882 (18 months at $49/month). Payback: 0.7 months. Gross margin: 88%.
Business Model
SaaS subscription
Monetization Path
$49/month per monitored mailbox. Volume discount at 5+ mailboxes. Annual plan at 2 months free.
Revenue Timeline
First dollar: week 3 via 60-day trial conversion. $1k MRR: month 3. $5k MRR: month 7. $15k MRR: month 12.
Estimated Monthly Cost
Vercel: $20, Supabase: $25, Azure AD app registration: $0, Stripe fees: ~$25, Resend: $10. Total: ~$80/month at launch.
Profit Potential
Full-time viable at $8k–$15k MRR. High LTV due to deep M365 workflow dependency.
Scalability
High — Graph API polling scales to thousands of mailboxes; migrate to Graph change notifications (webhooks) at 500+ mailboxes for efficiency.
Success Metrics
Week 2: 5 M365 businesses in beta. Month 2: 25 paid mailboxes. Month 4: less than 15% monthly churn.
Launch & Validation Plan
DM 20 M365 SMB admins on LinkedIn with a 30-second Loom demo; offer 60-day free trial before any code is written.
Customer Acquisition Strategy
First customer: reply to every r/sysadmin and r/Office365 post asking about Outlook-to-SharePoint automation with a direct link to the demo and 60-day free trial offer. Ongoing: Microsoft AppSource listing, LinkedIn content targeting M365 admins, YouTube tutorial targeting 'auto save Outlook attachments SharePoint'.
What's the competition?
Competition Level
Medium
Similar Products
Power Automate (requires IT/developer to configure, expensive per-flow pricing), Zapier Outlook integration (no SharePoint file routing logic), KurJun (SharePoint-only, no Outlook routing) — none offer a visual rule builder for non-technical M365 users.
Competitive Advantage
No IT or Power Automate expertise required — any office manager can connect and configure rules in under 5 minutes.
Regulatory Risks
Graph API access to mailboxes triggers GDPR considerations for EU customers — document that attachment content is not stored beyond the routing operation and provide a data processing agreement template.
What's the roadmap?
Feature Roadmap
V1 (launch): M365 OAuth, routing rules, audit log, Vercel Cron sync. V2 (month 2-3): multi-mailbox per account, Slack failure alerts. V3 (month 4+): Microsoft AppSource listing, Teams channel routing.
Milestone Plan
Phase 1 (Week 1-2): Graph API auth, sync engine, rules engine. Phase 2 (Week 3-4): rules builder UI, audit log, Stripe billing. Phase 3 (Month 2): 20 paid mailboxes, AppSource submission started.
How do you build it?
Tech Stack
Next.js, Microsoft Graph API SDK for Outlook and SharePoint, Supabase for rules and audit log, Stripe for billing, Resend for notifications — build with Cursor for Graph API integration, v0 for rules builder UI.
Suggested Frameworks
@microsoft/microsoft-graph-client, MSAL Node, node-cron
Time to Ship
2 weeks
Required Skills
Microsoft Graph API OAuth, SharePoint file upload API, Next.js, Supabase, Stripe.
Resources
Microsoft Graph SDK docs, MSAL Node quickstart, SharePoint REST API docs, Supabase auth docs.
MVP Scope
app/api/auth/microsoft/route.ts (MSAL OAuth handler), app/api/sync/route.ts (Graph poll and route trigger), lib/graph.ts (Graph SDK wrapper for mail and SharePoint), lib/rules-engine.ts (rule matching logic), app/dashboard/page.tsx (connected mailboxes and audit log), app/rules/page.tsx (rule builder UI), lib/db/schema.ts (mailboxes, rules, audit_events tables), .env.example (Azure app client ID and secret, Supabase URL, Stripe key).
Core User Journey
Connect M365 via OAuth -> build first routing rule in 3 minutes -> first attachment auto-routed in next email cycle -> upgrade to paid within 14-day trial.
Architecture Pattern
Cron job polls Graph API for new emails with attachments -> rules engine matches sender/subject/type -> Graph API uploads file to SharePoint path -> audit event written to Supabase -> failure triggers Resend alert.
Data Model
User has many ConnectedMailboxes. ConnectedMailbox has many RoutingRules. RoutingRule has conditions (sender, subject, file_type) and target SharePointPath. AuditEvent belongs to one ConnectedMailbox with status and matched_rule_id.
Integration Points
Microsoft Graph API for Outlook mail and SharePoint files, MSAL Node for OAuth, Supabase for rules and audit log, Stripe for billing, Resend for failure alerts.
V1 Scope Boundaries
V1 excludes: Teams channel routing, calendar attachment handling, mobile app, white-label reseller, API access for system integrators, bulk historical email processing.
Success Definition
A non-technical office manager connects their M365 account, sets up 3 routing rules, and has attachments automatically appearing in the correct SharePoint folders for 30 consecutive days without any founder intervention.
Challenges
Microsoft AppSource review for Graph API apps takes 4–8 weeks — launch direct via self-service OAuth link first and pursue AppSource listing in parallel as the growth channel.
Avoid These Pitfalls
Do not request broad Graph API permissions in v1 — scoped mail.read and files.readwrite is sufficient and reduces Azure AD admin consent friction. Do not build team multi-mailbox management before validating single-mailbox value. Finding first 10 paying customers requires direct LinkedIn outreach to M365 admins — r/Office365 posts alone will not convert fast enough.
Security Requirements
Supabase Auth with Microsoft OAuth. Access tokens AES-256 encrypted at rest in Supabase. RLS on all tables scoped to user_id. Rate limit sync endpoint to 1 call per mailbox per 5 minutes. GDPR: attachment content never stored, audit log purged after 90 days on request.
Infrastructure Plan
Vercel for Next.js app and API routes plus Cron, Supabase for Postgres and auth, Sentry for errors, GitHub Actions for CI, Vercel preview for staging.
Performance Targets
200 mailboxes at launch cap, 2,000 sync calls/day. Graph API call under 1s. Dashboard under 2s LCP. Supabase connection pooling via pgBouncer at 100+ mailboxes.
Go-Live Checklist
- ☐Graph API permission scopes reviewed and minimized.
- ☐Stripe payment and mailbox activation tested end-to-end.
- ☐Sentry error tracking live with Graph API error alerts.
- ☐Vercel Cron health check confirmed running every 5 minutes.
- ☐Custom domain with SSL active.
- ☐Privacy policy and data processing terms published.
- ☐5 beta M365 admins signed off on routing accuracy.
- ☐Rollback: previous Vercel deployment tagged in dashboard.
- ☐LinkedIn launch post and r/Office365 reply drafted.
First Run Experience
On first run: dashboard shows a demo connected mailbox (demo@contoso.com) with 3 pre-seeded audit events showing routed PDFs and one failed routing event. User sees the rule builder pre-populated with a sample sender-domain rule pointing to a mock SharePoint path. User can click through the full demo audit log and rule editor without connecting their own M365 account. One-click Connect Microsoft 365 button is prominent and starts real OAuth immediately when clicked.
How to build it, step by step
1. Define schema: connected_mailboxes (id, user_id, email, access_token_encrypted, refresh_token_encrypted), routing_rules (id, mailbox_id, conditions jsonb, sharepoint_path), audit_events (id, mailbox_id, rule_id, filename, status, created_at). 2. Register Azure AD app with mail.read and sites.readwrite.all delegated permissions and configure redirect URI. 3. Run npx create-next-app and install @microsoft/microsoft-graph-client, @azure/msal-node, Supabase JS, Stripe, Resend. 4. Build /api/auth/microsoft route: MSAL authorization code flow, store encrypted tokens in Supabase. 5. Build lib/graph.ts: getNewEmailsWithAttachments() and uploadToSharePoint(path, buffer) using Graph SDK. 6. Build lib/rules-engine.ts: evaluate routing_rules conditions against email metadata and return target path. 7. Build /api/sync route: fetch new emails, apply rules engine, upload attachments, write audit events, alert on failures. 8. Set up Vercel Cron to call /api/sync every 5 minutes per connected mailbox. 9. Build app/rules/page.tsx: visual rule builder with sender/subject/file-type condition dropdowns and SharePoint path input. 10. Deploy to Vercel, connect a real M365 account, send a test email with PDF attachment, verify it appears in the target SharePoint folder and audit log shows success.
Generated
June 16, 2026
Model
claude-sonnet-4-6
Disclaimer: Ideas on this site are AI-generated and may contain inaccuracies. Revenue estimates, market demand figures, and financial projections are illustrative assumptions only — not financial advice. Do your own research before making any business or investment decisions. Technology availability, pricing, and market conditions change rapidly; always verify details independently.