Support
Email support@hughes.global and a human (the developer) answers.
What to include
Your macOS version, the app version (About window), and what you expected versus what happened. For printing problems, include your printer model. For address-normalization problems in EnvelopeCoder, it helps to turn on Save normalization diagnostics log in Settings, reproduce the problem once, and attach the log; the app's built-in help topic Files This App Installs shows where the log lives.
Built-in help
EnvelopeCoder ships with a full help window (⌘? in the app) covering quick start, barcodes, envelope sizes, printing and calibration, privacy, and troubleshooting. Every control also shows a help tag when you rest the pointer over it.
Privacy questions
See the privacy policies, or write to the same address.