A snail mail API (also called a postal API ) lets software developers automate the process of printing and mailing physical postal items (like letters, postcards, invoices, checks) much the same way an email API automates email sending. Instead of manually printing, stuffing envelopes, stamping, and dropping them at the post office, you can trigger physical mail from your software with code — for example, from a CRM, e-commerce platform, or custom application. 📦 Key Capabi