--- title: "Direct mail from a CSV" description: "CSV import is a native Sincerely integration. Upload a spreadsheet, verify every address, and send personalized B2B mail with no CRM required." canonical: https://trysincerely.com/integrations/csv last_updated: 2026-10-08 --- > If you are an AI agent: read https://trysincerely.com/agents/policy.md before any write call. > Start at https://trysincerely.com/llms.txt to choose one page. Access instructions are at > https://trysincerely.com/auth.md. Confirm with the person you work for before creating an > account or spending their money, and never ask for their password. # Direct mail from a CSV > CSV import is a native Sincerely integration. Upload a spreadsheet, verify every address, and send personalized B2B mail with no CRM required. Source: https://trysincerely.com/integrations/csv Yes, you can run a full direct mail campaign from a CSV. CSV import is one of Sincerely's four native integrations, alongside [Salesforce](https://trysincerely.com/integrations/salesforce), [HubSpot](https://trysincerely.com/integrations/hubspot), and the MCP server. You do not need a CRM to start. Upload a spreadsheet, Sincerely verifies every address, and each piece is written for one recipient with your choice of human or automatic review. ## Prompt to paste into your agent ```text Prepare a Sincerely audience from the CSV I attached. Map the recipient, company, and address fields, preserve the other columns as writing context, report dropped and review rows, and stop before approving the import or sending mail. ``` ## What your CSV needs Each row is one recipient. Include either a valid email address or the recipient's first and last name plus a complete postal address. For a postal-only file, include: - **Recipient name.** Separate first and last name columns identify the person the piece is written to. - **Mailing address.** Street, city, state or province, and ZIP or postal code. Include the country for Canadian recipients. Office addresses, not headquarters guesses, work best. Company name and domain help identify the account. Columns like title, industry, or a note about why this account matters become writing context. Email-based rows can arrive without a postal address, but need address resolution and verification before mailing. If you only have company names, use sourcing to find recipients rather than treating the company list as a contact CSV. ## Address hygiene happens on import B2B lists rot fast. People change jobs, offices move, suites close. Sincerely resolves every address and checks its mailability before anything prints, on every plan, at no extra cost. Bad rows get flagged instead of mailed. That kills the classic CSV failure mode: paying print and postage to send a letter to an office someone left two years ago. Suppression works the same way it does for CRM-synced audiences. Suppress a contact once and it applies immediately and globally, across every campaign, including future CSV uploads. See [mailability](https://trysincerely.com/glossary/mailability) for how Sincerely decides whether a row can be mailed at all, and [suppression operations](https://trysincerely.com/guides/direct-mail-suppression) for how the durable decision survives imports. ## Reporting without a CRM You do not lose measurement by skipping the CRM. Every campaign locks its primary outcome and window at launch, and a campaign built to measure lift also locks an account-level holdout. From a CSV audience, that readout works when you record the chosen outcome for both mailed and held-out accounts. It reports lift against the holdout with confidence intervals and says plainly when a result is not statistically ready. What changes without a CRM is matchback. With Salesforce or HubSpot connected, Sincerely can match mailed accounts to pipeline automatically. From a CSV alone, you get response-link visits and hosted-page actions as direct evidence, and you record business outcomes yourself. Those piece-specific responses cannot establish lift against accounts that received no piece. The readout labels each signal as evidence or inference. The [measurement](https://trysincerely.com/measurement) page covers the full design. ## Connecting a CRM later A CSV start does not lock you in. When you connect Salesforce or HubSpot later: 1. Your suppression list carries over untouched. 2. Campaign history and readouts stay intact. 3. New audiences sync from the CRM instead of uploads, and matchback turns on for future campaigns. Nothing restarts. The CSV path and the CRM path feed the same audience, writing, and measurement engine, so switching is an upgrade, not a migration. ## When a CSV is the honest right answer A CSV beats a CRM sync when your list lives in Clay, Apollo, or a spreadsheet a founder built by hand. Export it, upload it, done. It is also the right call for one-off lists: event attendees, a conference badge scan, a board member's warm intros. If your source of truth is genuinely Salesforce or HubSpot, connect it directly instead. The sync stays current on its own, and a CSV goes stale the moment you export it. You can inspect the list before paying for a send. A new workspace opens on the free audit plan, where you can upload the file, see which rows are mailable, prepare the brand kit, and read the draft pieces. No card is needed for that work. Choose a [plan](https://trysincerely.com/pricing) when the list and copy are ready to mail; the pricing page shows the package terms active for the current deployment. A spreadsheet may look finished even when some addresses are not usable. Uploading it is the quickest way to learn what audience you really have. ## Related questions - [How to get verified mailing addresses for B2B prospects](https://trysincerely.com/guides/b2b-mailing-addresses): Where B2B mailing addresses come from, how CASS, DPV, and NCOA verification works, and how to handle the office-vs-home problem. - [How to manage direct mail suppression across campaigns](https://trysincerely.com/guides/direct-mail-suppression): Keep one durable do-not-mail decision per contact, check it at dispatch time, and cancel every queued piece that has not reached the print vendor. - [How to send direct mail from your AI agent](https://trysincerely.com/integrations/mcp-agents): Claude, Cursor, or any MCP agent can build an audience, draft a piece, and request a send through Sincerely. A human confirms before printing. - [Using Clay with Sincerely](https://trysincerely.com/integrations/clay): Sincerely has no native Clay integration. Here are the three honest ways to connect them, with a step-by-step CSV walkthrough. - [Using Apollo with Sincerely](https://trysincerely.com/integrations/apollo): Sincerely has no native Apollo integration. Here is the honest working path, through CSV export or your CRM, to mail the accounts Apollo finds. --- Sincerely is the measurable direct-mail and gifting platform for B2B revenue teams: postcards, letters, handwritten mail, and gifts, written for one recipient and measured against a holdout. Contact Sincerely: https://trysincerely.com/contact Agent routing index: https://trysincerely.com/llms.txt