Features
Everything required to put paper in the mail — and to let software do it for you.
For people
Upload PDF or compose
Drop a finished document or write a letter in a focused editor.
Email to Letter
Get a unique inbox and turn matching emails into First-Class letters. Choose approval or autosend, set spending limits, and preview or download your letters. Explore Email to Letter.
Email to Postcard
Turn emails into either postcard type with saved rules, artwork, review or authorized autosend. Open Email to Postcard.
Address book
Save senders and recipients. Load them into From or To on the send screen.
Save from send
One click on the send screen stores sender or recipient in the address book.
Tracking
Job statuses from queued through mailed, with USPS tracking when available.
For mail classes
First-Class
#10 letters. First-page price plus additional pages.
Certified Mail
Certified piece with the first page included; additional pages priced separately.
Electronic Return Receipt
Optional ERR add-on on Certified pieces.
Postcards
Send one 5.5 × 4.25 inch single-sided or 8.5 × 5.5 inch double-sided postcard, with full color included. How to send a postcard.
More products
Flats, statements, payment coupon sheets, other postcard sizes and custom print options. Explore the catalog.
For software
REST API
Create letters, list jobs, validate addresses, quote prices.
API keys
lbl_live_ and lbl_test_ keys, hashed storage, revoke anytime. CSV lists via the API.
MCP
Send mail from Claude, Cursor, and other clients with an API key, org credits, or a Square checkout.
Card payments via Square
Pay by card in the workspace. Stablecoin payments available for developers.