MailBridge for Accounting (MAPIless Email Relay)
9/10
Demand Score
Invoice, PO, and statement emails fail during cutovers, VDI rollouts, or Outlook updates—delaying cash collection and vendor communications.
9/10
Blue Ocean
Competition Level
$79-299
Price/Month
Predicted customer spend
6 days
Time to MVP
Difficulty: Moderate
The Problem
A local MAPI shim and cloud relay that makes any accounting app “think” Outlook is present while actually sending through Microsoft Graph or Gmail API. It fixes 32/64‑bit MAPI mismatches, missing Outl
🔗 Validated by Real User Complaints
This problem has been verified through 1 real user complaints:
Competitor Landscape
- Native Outlook/MAPI integration in accounting apps
- QuickBooks built‑in email via Outlook/SMTP
- SMTP relays (SendGrid/Mailgun) without MAPI compatibility
- Generic Outlook add‑ins
- Microsoft Graph connectors (not MAPI-compatible by default)
Must-Have Features for MVP
Local MAPI shim with 32/64‑bit compatibility
Graph/Gmail API relay with OAuth and modern auth
Reliable queueing/retry with offline support
Per-template sender/domain mapping and DKIM signing
Delivery, open, and bounce analytics with audit trails
Attachment size handling and secure links for large files
⚠️ Potential Challenges
- Enterprise OAuth/Graph consent and tenant policies
- MAPI edge cases across vendors/bitness
- Deliverability (SPF/DKIM/DMARC) alignment
- PII handling in attachments and compliance
Risk Level: Moderate
🎯 Keys to Success
- >99.9% send success rate from accounting apps
- 50%+ reduction in email-related support tickets
- Improved DSO via uninterrupted invoicing
- Compliance-ready logging accepted by auditors and IT
Ready to Build This?
This moderate-difficulty project could be your next micro-SaaS success.