Single mailing
Send a letter online
The homepage covers the one-letter workflow: upload a PDF, enter recipient information, select Certified Mail options and submit. See current pricing and get an estimate.
See online mailingServices & buying guides
Choose a mailing workflow that fits.
A single letter, a recipient-matched batch, an existing software workflow and the evidence after mailing all raise different questions. Start with the guide that matches what you’re trying to do.
Multiple recipients
Batch Certified Mail
Learn how a recipient spreadsheet and one PDF per person work together, what to validate before submission and how to test a batch before it goes live.
Explore batch mailingSystem integration
Certified Mail API & SFTP
Review the published setup path for API or secure file transfers, sample proofing, testing and the difference between event tracking and integration status.
Explore integrationsSignature service
Electronic Return Receipt
Understand the optional USPS signature service, the PDF report it creates, what is not included and how to estimate the added cost.
Understand Return ReceiptDocumentation
Proof of mailing
Compare the USPS acceptance scan, tracking history, delivery confirmation, electronic signature report and notarized affidavit of mailing.
Review mailing evidenceLegal office workflow
Certified Mail for attorneys
See how case references, the Clio integration, staff handoffs and a retrievable record set fit into a law firm’s mailing process.
Explore the legal workflowA few useful facts
Good to know before you choose.
Timing: complete orders submitted before 5:00 p.m. Eastern on a USPS business day can qualify for same-business-day printing and mailing. Same-day refers to USPS acceptance, not delivery.
Evidence: mailings include a notarized affidavit of mailing. USPS acceptance and tracking records document postal events; whether they satisfy a legal rule depends on that rule.