Lob Address Verification vs Sincerely

Lob Address Verification checks address data to help determine whether addresses can be delivered. Its APIs validate one address or a batch, and Lob says it can also check and standardize addresses while customers enter them on a website. Results can add delivery and geographic details, including ZIP+4, carrier route, address type, latitude and longitude, plus a confidence score based on its mail delivery data. The product page lists delivery data for more than 240 global territories and USPS CASS certification. Integrations include AV Elements, Shopify Address Cleanser, Airtable Address Cleanser and Zapier; the interactive demo provides examples in cURL, TypeScript, Node, Ruby, Python, PHP, Java, Elixir and C#. Lob says it encrypts data in transit with TLS 1.2+ and at rest with AES-256, and provides automatic redaction and data retention policies. Developer has no subscription fee; listed paid pricing starts at $20/mo (annual). A 30-day Enterprise trial is available for high-volume senders; print and postage are billed separately at discounted Enterprise rates.

Sincerely is web software for B2B direct-mail campaigns using CRM or CSV audiences, personalized printed pieces, and measurement against account-level holdout groups. Salesforce and HubSpot sync account, contact, opportunity-stage, and campaign-membership data, and CSV import is supported. The product drafts personalized writing from account research and links each factual claim to a source. Drafts require human approval before printing, and edits are versioned. Postcards and letters can be mailed; handwritten notes and gifts are not live because their fulfillment adapters are not built. Address verification and correction are included on every plan, with low-confidence addresses routed for review. Every plan includes account-level holdouts, and Sincerely says five of eight campaign types measure lift against a holdout. When a plan reaches its monthly cap, live campaigns pause rather than print additional pieces. The free Audit plan supports imports, a mailability audit, brand designs, and draft editing, but cannot mail. Paid plans start at $250 a month; Pilot is 199.00 USD once.