--- title: "Direct mail for teams selling to Y Combinator companies" description: "Write to the YC operator who owns a new problem with a piece built on one change at their company, researched and mailed by Sincerely after you approve it." canonical: https://trysincerely.com/for/yc-companies last_updated: 2026-10-18 --- > 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 for teams selling to Y Combinator companies > Write to the YC operator who owns a new problem with a piece built on one change at their company, researched and mailed by Sincerely after you approve it. Source: https://trysincerely.com/for/yc-companies Founders and startup operators get a lot of pitches, and many open with the batch or the funding round. Neither shows that the sender understands the company. A piece worth sending leaves out the YC name. It names one operating change inside the business and offers one useful idea to the person who now owns it. Sincerely starts each postcard or letter from that change. It finds the companies, writes from a dated signal, prints and mails the piece, and sends follow-ups on your schedule. You approve every word, and nothing prints until you launch. If you sell products or services to Y Combinator companies, this guide is for you. It does not cover YC founders mailing their own customers. Sincerely is not affiliated with Y Combinator. ## A postcard written for a startup operator ![Printed postcard from Relaybench, a support operations company, to Priya Raman, head of support at Brindlepath, opening with: Your support team is hiring across three time zones while the product is moving into larger accounts.](https://trysincerely.com/samples/for-yc-companies.webp "A fictional sample: a printed postcard from a made-up support software company to the head of support at a growing startup, with the researched words underlined.") What makes it work: - It never mentions YC. It opens with two changes at Brindlepath. The company is hiring support staff across three time zones, and its product is moving into larger accounts. - It goes to the head of support, who owns the problem now, instead of the founder whose name is public. - It names a consequence the reader already knows. Handoffs get harder to track before response times get longer. - It offers one thing, a simple ownership model for support teams at this stage. It asks one question and says how to reply. A postcard suits this message because it is public and simple. Use a letter when the argument needs room or privacy. A founder-to-founder note works when the sender has a real point of view and will follow up themselves. The [founder-led sales playbook](https://trysincerely.com/playbooks/founder-led-sales) covers that note. ## Write to whoever owns the problem today At an early company, the founder is often the right recipient. That changes as the team grows. | Company situation | Likely recipient | | ---------------------------------- | ------------------------------------- | | Founder still owns the problem | Founder or co-founder | | First specialist leader is in seat | The new functional leader | | Function has a real team | Functional executive or operator | | Purchase crosses several teams | Operational owner, then key reviewers | | Existing evaluation has stalled | The person already leading the work | A letter to the founder looks like weak research once a CFO, security leader, or head of sales owns the problem. Write to one person unless the purchase crosses several teams, and then start with the operational owner. The [new-executive play](https://trysincerely.com/playbooks/new-executive) covers the moment a specialist leader takes ownership. ## Write when the company outgrows its setup YC says companies enter its program at different stages, so the batch label only tells you when a company joined. Start with an operating change your product can help with: - A small founder-led company hires its first operations, finance, sales, or people leader. - A growing company adds several jobs in one function or location. - A product launch creates a new support, security, compliance, or go-to-market burden. - A larger company opens an office, enters a market, or adds an enterprise product. - A named evaluation or conversation goes quiet after real engagement. The [YC Startup Directory](https://www.ycombinator.com/companies) can confirm the company and its public description. [YC startup jobs](https://www.ycombinator.com/jobs) and the company's own careers page show where it is hiring. Record the source and date with the account, so a reviewer can see why the piece goes out now. ## Keep the badge and the stale list out of it A careful seller has two worries here. The first is sounding like you use the YC name to sell. The connection may help you find the company, but it should rarely be the point of the piece. Do not imply that YC introduced you, endorsed your product, or shared private information. Do not write "fellow YC founder" unless that relationship is true and relevant. The second is mailing a saved YC list after it has gone out of date. Before launch, confirm that the company is active, the recipient still works there, the signal is current, and the address still makes sense. Remove companies that no longer fit, even when the list gets shorter. The address needs the same care. Many YC companies are remote or hybrid, and some are newly incorporated. A profile may name a city and no mailing address. A registered address may belong to an agent, and a shared office may not pass mail on to the person. A verified delivery point does not prove the recipient works there. Check a contact page, job listing, event record, CRM note, or prior correspondence. Do not buy or infer a home address for cold outreach. The [B2B address guide](https://trysincerely.com/guides/b2b-mailing-addresses) covers the difference. ## Let Sincerely run the mail Sincerely runs the channel from the company list to the follow-up. You approve every piece and take the calls. - You start with companies that fit. Sincerely finds companies that match the kind of YC company you describe and qualifies each account. Only then does it add a few current founders or functional leaders. - Every piece has a dated reason. Sincerely collects sourced signals from company descriptions, hiring, launches, leadership changes, and your CRM history. It keeps each signal on the account record while you approve the audience. - Doubtful addresses wait for a person. Sincerely holds uncertain remote, shared-office, or registered addresses for review. - Each reader gets the argument for their role. Sincerely matches each draft to the company's stage. A founder who still owns the problem gets a different argument from the first finance or security leader. - Nothing prints by accident. A person reviews every claim. A piece prints only with an approved design, a passing address, budget headroom, and an explicit launch. - One objection covers every campaign. Campaign and one-off sends count toward the same frequency cap. When a person objects or leaves the company, one suppression stops mail from every campaign. - Your best customers can get a gift. For a founder who became a customer or sent a referral, Sincerely sends a gift with a personal note. The catalog has 46 items, prices start at $49, and you see the exact price before you confirm. See [gifts](https://trysincerely.com/gifts). ## See what works Sincerely records replies and meetings against each company, so you can see which pieces turn into conversations. A small founder-led list gets a descriptive report of replies and meetings as they happened. For a larger, repeatable program, define eligible accounts by the same stage and signal rules before you assign a holdout. Keep every person at one company in the same arm. Measure a near-term outcome, such as a qualified meeting or an accepted evaluation. Do not compare mailed YC companies with every other startup in the CRM, because the groups differ before the mail arrives. Sincerely locks one primary outcome and window and reports response and lift separately. It pools cohorts only when the qualification rule, message, outcome, and window stay comparable. The [B2B direct mail guide](https://trysincerely.com/guides/b2b-direct-mail-marketing) covers the method. ## Start with the YC companies already in your CRM Pick the accounts with a dated operating change, or describe the companies you want and let Sincerely find them. Each piece spends prepaid credits, and you see the count before it goes out. The [formats page](https://trysincerely.com/formats) lists what each format costs. If nobody on your team has time, Sincerely's team can [run the program for you](https://trysincerely.com/managed-direct-mail). To book a demo, [write to us](https://trysincerely.com/contact). ## Related questions - [Direct mail for founder-led sales](https://trysincerely.com/playbooks/founder-led-sales): How a founder chooses a small account list, writes a credible personal letter, follows up, and judges the results without overstating a tiny sample. - [The new-executive welcome play](https://trysincerely.com/playbooks/new-executive): Send a personal letter to an executive in their first 90 days, when they are rethinking the stack and nobody else is in their mailbox. - [B2B direct mail: how to run it, with campaign ideas](https://trysincerely.com/guides/b2b-direct-mail-marketing): How to run B2B direct mail marketing. When mail belongs, campaign ideas matched to real triggers, addresses, copy, send controls, and honest measurement. - [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 sell to a company after it raises funding](https://trysincerely.com/guides/how-to-sell-after-a-funding-round): Verify the financing, find the work it may enable, contact the people who own that work, and measure outreach without treating funding as buying intent. --- Sincerely is personalized direct mail and gifting for B2B revenue teams: postcards, letters, handwritten mail, and gifts, each written for one recipient. Contact Sincerely: https://trysincerely.com/contact Agent routing index: https://trysincerely.com/llms.txt Listings: https://www.g2.com/products/sincerely and https://www.producthunt.com/products/sincerely