---
title: "Proprietary deal sourcing with direct mail"
description: "How buyers and advisors run owner outreach by mail: the thesis, list size, waves you can follow up, calls after delivery, and what the numbers can tell you."
canonical: https://trysincerely.com/guides/proprietary-deal-sourcing
last_updated: 2026-10-11
---
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# Proprietary deal sourcing with direct mail

> How buyers and advisors run owner outreach by mail: the thesis, list size, waves you can follow up, calls after delivery, and what the numbers can tell you.

Source: https://trysincerely.com/guides/proprietary-deal-sourcing

Proprietary deal sourcing means reaching a business owner yourself, before an intermediary runs a sale. A mail program for it has four parts: a written thesis, a list of companies that fit it, letters sent in waves small enough to follow up by phone, and a record of every reply. The letter opens the door. The calls, the second letter, and the patience over months do most of the work.

![A funnel narrowing from thousands of companies contacted to 50 visited, 10 letters of intent, and 1 to 3 companies in diligence.](https://trysincerely.com/images/guides/proprietary-deal-sourcing.webp)

*In proprietary deal sourcing, thousands of contacts narrow to one to three companies in diligence, so size the list backwards from the conversations you need.*

This guide is for searchers, private equity firms looking for platforms or [add-on acquisitions](https://trysincerely.com/glossary/add-on-acquisition), family offices, and advisors who want a sourcing program rather than a one-off mailing.

## Why mail is in the mix

Start with an uncomfortable fact: most proprietary deals still begin with email. In [Search Investment Group's 2023 study](https://hadleyfamilycapital.com/wp-content/uploads/Search-Investment-Group-2023-Self-Funded-Search-Study.pdf) of self-funded searchers who bought a company, 68% of the deals that came from their own outreach started with a cold email, 12% with a cold call, and 8% with a letter. The sample is small, about 27 deals, so that 8% is roughly two of them. The direction is still clear. Email reaches thousands of owners a week, and letters reach hundreds. If volume is the goal, email wins.

Mail does a different job. Stanford's [2026 primer on search funds](https://cdn.prod.website-files.com/6455268783d6938b9451ea80/6a0c69fbc5155d301022362d_2026%20A%20Primer%20for%20Search%20Funds_vFinal.pdf) reports that owners' replies to email have fallen since the early 2020s as they receive more cold outreach, and that a letter sent before a call can work better than a cold call alone. One searcher who mailed 50 letters a week [wrote](https://hadleyfamilycapital.com/wp-content/uploads/Paul-Thomson-Stream-of-Consciousness-on-Search-Funds.pdf) that fewer than 5% of owners answered the letters, yet more than 80% of the owners he later called knew who he was. That is the case for a letter: it turns the call that follows into a warm one.

Mail is slower and costs more per contact than email. That is fine for this use. You are not trying to reach ten thousand people; you are trying to start a few dozen real conversations a year with owners who fit.

## Write the thesis first

Before any list, write down what you are looking for: industry, geography, size range, years in business, ownership type, and what rules a company out. A thesis that fits on half a page is specific enough to build a list from and specific enough to write a letter from. "Commercial HVAC service companies in the Mountain West, 20 to 100 employees, founder-owned, majority service revenue" is a thesis. "Lower-middle-market industrial services" is not.

## Size the list by the conversations you need

Work backwards. Stanford's primer describes a search in which a searcher may "contact thousands of companies, visit 50, submit a Letter of Intent to 10, and undertake due diligence on perhaps one to three." Decide how many first conversations you want in a year, then estimate how many letters it takes to get one.

Nobody can give you that rate honestly in advance. The published numbers are single searchers' own logs: one [Stanford case](https://hadleyfamilycapital.com/wp-content/uploads/ces-search-funds-best-practices-search-phase.pdf) recorded 256 responses to 3,404 letters in a first year, about half of them positive, and other searchers report under 5%. Figures of 20% or more for handwritten letters come from companies that sell them. Your rate depends on the industry, the list, the letter, and how well you follow up, so run a first wave of 100 to 200 letters, measure your own rate over the following three months, and size the rest of the program from that.

Some practical limits:

- A list of a few hundred companies that fit the thesis beats a few thousand that loosely fit. Loose fits produce conversations you will turn down.
- Each company needs a named owner and a mailing address you trust. Skip registered-agent addresses and anything addressed "to the owner of."
- Remove companies you already know, and any owner who has said no.

## Send in waves you can follow up

The bottleneck in owner outreach is rarely the letters. It is the calls after them. Size each wave to what you can follow up within two weeks of delivery: if you can make thirty careful calls a week, a wave of 60 to 100 letters every two or three weeks keeps you honest.

For printed letters in the United States, Sincerely receives delivery events from the print provider, and a confirmed delivery can raise a follow-up task, which Salesforce users can have written back to their CRM. Handwritten letters and Canadian mail report no delivery event, so plan those calls from the mail date. [Following up with business owners](https://trysincerely.com/guides/follow-up-with-business-owners) covers what to say and when to write again.

## Keep the record per company

For every company: why it is on the list, the fact the letter used, the date of each letter and call, every reply, and the next contact date. Over a year, this record answers the useful question: which reasons for putting a company on the list led to conversations. It also stops two people at the same firm from writing to the same owner in the same month.

Sincerely records replies and meetings against the company. Its default frequency cap allows no more than three pieces to one person in any 30 days across every campaign in the workspace, and suppression after a no takes effect at once.

## Read the numbers honestly

At a few hundred letters a year, any percentage is noise. Count instead: letters delivered where the print provider reports delivery, replies, first conversations, second conversations, and companies that reached an indication of interest or a letter of intent. Sincerely keeps the readout descriptive at that volume and says so. The [small-audience guide](https://trysincerely.com/guides/direct-mail-small-audiences) explains what numbers of this size can support.

A program that mails thousands of owners a year can answer a better question: did the letters cause conversations that would not have happened anyway? Sincerely can hold out a random set of companies in each campaign, mail the rest, and report the difference in replies or meetings booked with an interval. Choose that outcome before launch; it is locked once the campaign starts.

## Where Sincerely fits

The research and writing are what make owner letters expensive to do well. Sincerely researches each company on your list in public sources, keeps only facts with a date and a source, and drafts each letter from one of them. You approve the words, every claim sits beside its source in review, and nothing prints until a person launches. Letters go out printed or genuinely written by hand in the United States and Canada, and printed letters can carry a code to [a page made for each owner](https://trysincerely.com/guides/acquisition-landing-pages).

If you would rather not run the program yourself, Sincerely's team can run it for you. [Write to us](https://trysincerely.com/contact). The sender-specific detail is in the playbooks for [search funds](https://trysincerely.com/playbooks/search-funds), [private equity](https://trysincerely.com/playbooks/private-equity), [family offices](https://trysincerely.com/playbooks/family-offices), and [investment banks](https://trysincerely.com/playbooks/investment-banks).

## Related questions

- [How to write a letter to buy a business](https://trysincerely.com/guides/letter-to-buy-a-business): What a first letter to a business owner about buying their company should say: one fact, who you are, the ask, what to leave out, and a weak letter rewritten.
- [How to follow up with a business owner about selling](https://trysincerely.com/guides/follow-up-with-business-owners): After your letter arrives: when to call, what to say, when to write again, and what to do when a business owner says yes, not now, no, or nothing.
- [Direct mail for private equity add-on sourcing](https://trysincerely.com/playbooks/private-equity): For private equity firms and independent sponsors writing to founders about add-ons and new platforms: the thesis, the list, who signs, and follow-up.
- [Direct mail for search funds](https://trysincerely.com/playbooks/search-funds): For searchers writing to business owners, with guidance on list criteria, one sourced fact per letter, printed or handwritten letters, and stopping at a no.
- [What is proprietary deal flow?](https://trysincerely.com/glossary/proprietary-deal-flow): Proprietary deal flow is acquisitions a buyer finds by reaching owners directly, before an advisor runs a competitive sale. What it means and how it is built.
- [How to measure direct mail with a small audience](https://trysincerely.com/guides/direct-mail-small-audiences): Keep an account-level holdout, predeclare one outcome, and pool comparable cohorts when your B2B direct mail audience is too small to measure alone.

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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.

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