PostGrid API
PostGrid REST API — programmatic physical mail sending (letters, postcards, checks) and address verification, enabling agents to automate direct mail campaigns, compliance notices, and physical document delivery without manual print-and-mail workflows.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
SOC2 Type II. HIPAA BAA available for healthcare physical mail. TLS enforced. Test/live key separation is good security design. No scope granularity — live key has full account access including billing. US and CA data processing.
⚡ Reliability
Best When
You need to automate physical mail for compliance, legal notices, or direct mail campaigns where physical delivery is required or preferred.
Avoid When
Digital communication (email/SMS) meets your needs — physical mail is 50-100x more expensive per message than digital channels.
Use Cases
- • Agents sending compliance notices and legal documents as certified physical mail for regulated industries
- • Automated billing statements — agents generating and mailing PDF invoices to customers without physical printer management
- • Direct mail campaigns — agents triggering personalized postcard mailings based on CRM segmentation and behavioral triggers
- • Address verification — agents validating and standardizing mailing addresses before data entry or physical mail sends
- • Check disbursement — agents programmatically printing and mailing checks for refunds, payouts, or vendor payments
Not For
- • Digital-only communications — use SendGrid or Twilio for email/SMS at fraction of the cost
- • International direct mail at scale — PostGrid is primarily US and Canada focused; international support is limited
- • Greeting card or gift mailings — use Thankster or Sendoso for personal/gifting physical mail use cases
Interface
Authentication
API key from PostGrid dashboard. Separate test and live API keys. Test mode simulates mail without physical sending — free for development. Live API key triggers actual mail printing and delivery at cost.
Pricing
Pay-per-piece pricing with no monthly minimums. Volume discounts for 500+ pieces/month. Address verification: $0.007/verification. Competitive with Lob.com on pricing.
Agent Metadata
Known Gotchas
- ⚠ Live API key triggers real printing and billing — never use live key in development; test key is safe for all testing
- ⚠ Mail jobs are irreversible after submission — implement confirmation step before sending live mail batches
- ⚠ PDF template must be print-ready — safe zone margins and bleed areas required or mail may be rejected at print
- ⚠ Delivery tracking is approximate — USPS and Canada Post tracking is included but granularity varies by mail class
- ⚠ Address verification should run before mail creation — invalid addresses cause print job failures that still consume credits
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for PostGrid API.
Scores are editorial opinions as of 2026-03-06.