A Civil-Law Approach to Unsolicited Sales Emails: Transferring Receiver Costs to Senders

From 2026-06-01, the Institute for Social Vision Design (hereinafter "the Institute" or "ISVD") begins operating a regulation that, against unsolicited sales communications sent (i) through the contact form on its website and (ii) directly to its published email addresses, asserts civil claims based on contract and tort theories: the Sales Email Policy.

The regulation's framework:

• Contact-form submissions under the "Sales / Business Proposals" category require explicit checkbox consent treating the submission as an application for a paid consultation (JPY 10,000 / 30 minutes excl. tax)
• Submissions under non-sales categories that contain sales content trigger a fee of JPY 10,000 for breach of the mandatory "no sales content" consent. Intentional category misuse is doubled to JPY 20,000
• Direct submissions to published email addresses (out-of-form) incur tort damages of JPY 10,000 under Civil Code Art. 709 for business interference
• An objection filed within 14 days immediately withdraws the claim; ISVD reviews and notifies the result within 30 days

The full suite (regulation text, implementation code, operations templates, database DDL) is released as open source (CC BY 4.0 + MIT). Other organizations can reference and adapt it. The repository is at github.com/correlate000/sales-email-policy.

This regulation is positioned not as a standalone defense, but as a social-implementation trial of a civil-law approach to structural correction of the unsolicited-sales-email problem.

The economic structure of the sales-email problem

Unsolicited sales emails are commonly understood as "individually minor nuisances." This framing misses the underlying economic structure.

According to statistics from Japan's Ministry of Internal Affairs and Communications, the average user receives approximately 9 unsolicited messages per day. At a minimum of 30 seconds per message for confirmation and response, receivers spend roughly 15 hours per year handling spam. For research institutions, knowledge workers, and NPO operators who use email heavily for business, this burden is even greater.

The essence of the problem is not the cumulative review labor of receivers, but the cost asymmetry between sender and receiver.

Current

Sender~¥0

Cost per outbound message

Receiver~¥100

Cost per inbound review and response

After Policy adoption

Sender~¥10,000

Expected cost including invoice risk

Receiver¥10,000

Recovered via claim

For the sender, the cost of sending a single message is effectively zero. For the receiver, the confirmation cost is hourly rate × 30 seconds, or roughly JPY 100. This overwhelming sender-side advantage makes unsolicited outreach economically rational. As long as the expected value is positive (rejection rate × 0 cost + acceptance rate × benefit > 0), sales organizations will continue to send.

Limits of existing remedies

Existing responses to this structure fall into four categories.

What these existing remedies share is that they do not alter sender economics. As long as sending costs zero, "rejection without loss" remains true for senders. Receivers continue to accumulate symptomatic treatments (filters, blacklists) and exhaust themselves.

The possibility of a civil-law approach

Distinct from administrative enforcement and technical filtering, a third path exists: structural correction via civil law and contractual framing.

The logic is straightforward. Construct a regulation that transfers receiver-side actual costs to senders, and publish it on the website. Senders bear a duty of care, under prevailing social norms, to consult the regulation before sending. A send that violates this duty creates a civil-law claim (contract or tort).

When this structure is implemented, sender economics changes. The expected cost of sending increases by "claim risk × claim amount." Senders gain an incentive to "send only what is truly valuable."

Richard Thaler and Cass Sunstein, in 実践行動経済学 : ノーベル経済学賞を受賞した賢い選択をうながす「しかけ」 (Nudge, Japanese edition) (Nikkei BP), demonstrated that changing the choice architecture (how options are presented to people) can substantially alter behavior. This Policy applies the same insight to the sender-side decision architecture. By rewriting the default of "JPY 0 sending cost" to "JPY 10,000 claim risk," the policy redesigns the rational choice landscape for senders.

However, this approach faces technical legal challenges. Can website publication alone bind senders? How should damages be calculated? How do you distinguish "sales" from "partnership inquiries"? How should erroneous claims be challenged? The next section examines ISVD's design choices for each.

Legal construction by submission path (4 paths + 1 additive)

In ISVD's regulation, claims are constructed under different legal bases per submission path. Each path's basis is self-contained and does not depend on another.

Path	Legal Basis	Construction	Strength
Via Contact Form, sales category, consent	Civil Code Art. 522 et seq. + Art. 548-2	Contract	★★★
Form misuse	Civil Code Art. 548-2 + Art. 95(3)	Contract + representation breach	★★★
Out-of-form, first time	Civil Code Art. 709 + Art. 1(2) good faith + Anti-Spam Act Art. 3	Tort	★★★
Out-of-form, resubmission	After Policy Citation Notice + 14 days, contract by analogy	Contract by analogy	★★★
Category Misuse (additive)	Above + intentional misconduct (2×)	Intentional misconduct additive	★★★

The basis and key issues for each construction:

Form-based, sales category: The sender explicitly consents via checkbox, directly satisfying Civil Code Art. 522 et seq. (contract formation) and Art. 548-2(1) (standard-form contract incorporation). The strongest construction.

Form misuse: The sender consents to "no sales content" checkbox and then sends content contradicting that consent. The mismatch between the consent representation and the actual content grounds the claim. Civil Code Art. 95(3) restricts mistake-based recission to cases without gross fault.

Out-of-form, first time (direct to published email): This is the most carefully designed path. It uses the following three-step syllogism:

1. Published email addresses are disclosed for receiving operationally necessary communications (press interviews, recruitment applications, communications from existing counterparties, official communications, partnership consultations). They are not intended to receive sales communications.
2. Senders bear a duty of care, under prevailing social norms between business entities, to confirm the website-published regulation before sending. This duty arises under the principle of good faith (Civil Code Art. 1(2)) and the legislative intent of the Anti-Spam Act Art. 3 (opt-in regulation).
3. A sale-related send that violates this duty constitutes unlawful interference with ISVD's operations. A damages claim arises under Civil Code Art. 709 (tort).

A key design point of this path is that it rejects the "unjust enrichment (Civil Code Art. 703)" construction. Art. 703 requires "a person who has received a benefit through another's property or services." Unsolicited sales-email senders receive no economic benefit from the recipient. The benefit requirement cannot be met. The construction is therefore legally fragile. ISVD instead uses Civil Code Art. 709 tort to construct the claim as damages for business interference.

Out-of-form, resubmission: After ISVD sends a "Policy Citation Notice" in response to a first submission, if the sender resubmits within 14 days without indicating cessation, contract construction applies by analogy.

Category misuse (additive): When the sender is determined to have intentionally selected the wrong category on any of the above paths, the amount is doubled. Because the burden of proof for "intent" lies with ISVD, doubled application is realistic only in cases of clear bad faith.

Damage calculation basis

The question "is JPY 10,000 reasonable as actual-cost recovery?" will inevitably be argued in litigation. ISVD publishes the calculation as an annex to the regulation.

• Content review (including exception and safe-harbor screening): 30 min × JPY 3,000/h = JPY 1,500
• Evidence preservation (header-inclusive archival, Drive tamper-proofing): 15 min × JPY 3,000/h = JPY 750
• Policy Citation Notice drafting and delivery (out-of-form path): 20 min × JPY 3,000/h = JPY 1,000
• Recording to violations database: 10 min × JPY 3,000/h = JPY 500
• Implementation of blocking measures: 5 min × JPY 3,000/h = JPY 250
• Invoice generation, PDF, delivery: 30 min × JPY 3,000/h = JPY 1,500
• Labor subtotal: JPY 5,500
• Allocation of legal audit, policy operation, and objection-handling overhead: JPY 4,500
• Total: JPY 10,000

The hourly rate of JPY 3,000 is calculated as the lower bound of mid-tier managerial cost in Japanese SMEs: approximately JPY 4,000,000 annual compensation ÷ 2,000 statutory working hours × overhead multiplier of 1.5. By time-stamping actual case-by-case work logs, ISVD builds the evidentiary base for damage proof.

Publishing this calculation has two effects. First, it prepares for damages proof in litigation. Second, it transparentizes the deterrent. For senders, knowing "the claim amount has a clear basis" raises the bar for ignoring the claim.

Safe harbor (preventing over-capture)

A civil-law approach carries the risk that overly broad regulation captures good-faith partnership inquiries. Article 2 Section 2 of the regulation specifies four categories that signals alone do not classify as sales communications.

1. Partnership proposals that directly connect to ISVD's domains of activity (social-issue research, public-asset revitalization, NPO operations, statistical analysis, education-sector partnerships, PPP/PFI) with specific reference
2. Press, education-sector, and public-interest corporation communications for interview or official purposes
3. Counterparties with transactional or consultative records with ISVD within the past 12 months
4. Communications with individuated context, not templated sales boilerplate

This safe harbor narrows the regulation's reach to "formal, templated, unsolicited sales communications." Good-faith partnership inquiries are received via a separate path under Article 8 ("Partnership and Collaboration").

Objection procedure (immediate-withdrawal type)

Objections can be filed in writing (email accepted) within 14 days of receiving the invoice. Upon receipt, the claim is deemed immediately withdrawn, and ISVD notifies the review result within 30 days. If the objection is accepted, the withdrawal continues; if rejected, a new invoice is issued.

This design has two intents. First, asymmetric dispute-cost resolution. By giving the receiver (the Institute) the constant option to "withdraw the claim and end the dispute," litigation costs do not explode on the receiver side. Second, distributed operational burden. Assuming roughly 50 violations per year, the design avoids breaking down under small-organization operation.

Open-sourcing and social implementation

The regulation suite is published under dual licensing: CC BY 4.0 (policy text) and MIT (code). Other organizations can reference, adapt, and adopt it.

Open-sourcing has three layers of significance.

First, individual-case defense. ISVD itself, as a research institution, can concentrate its attentional resources on its core mission (social-issue research) rather than spending 50 hours per year on sales-email handling.

Second, social implementation of regulatory design. The Civil Code Art. 709 concept of "business interference" may, through this regulation's operation, gain case-law material for adaptation to the digital sales-email context. Japanese case law has rarely positively affirmed "unsolicited sales emails = business interference + damages." ISVD's operation of a refined design with objection procedures, damage calculation, staged construction, and safe harbor may contribute to case-law accumulation.

Third, a propagation template for other organizations. Research institutions, NPOs, and individual practitioners with the same challenges can reference and adapt the regulation. The more organizations follow ("ISVD does it, so should we"), the more the social norm around the sales-email problem may shift. Civil regulatory accumulation may prove more effective than individual administrative complaints.

Remaining uncertainties

The legal validity of this regulation is ultimately for the competent court to determine. Three uncertainties remain:

1. Case-law accumulation on business interference: Whether the layered construction of Civil Code Art. 709 + good faith + Anti-Spam Act Art. 3 is recognized as "unlawful interference with ISVD's operations."
2. Social-normative reasonableness of JPY 10,000: The calculation is presented, but it depends on judicial discretion.
3. Enforcement against overseas senders: The jurisdiction clause is practically uncollectible. The regulation is accepted as a deterrent tool only.

These lie outside regulatory design; they are issues to be observed through operation and case-law accumulation.

Conclusion

Unsolicited sales emails are not "individual nuisances" but a social problem sustained by "structural sender/receiver cost asymmetry." Existing remedies remain symptomatic and do not alter the structure.

The civil-law approach attempts an economic-structure rearrangement that transfers receiver-side actual costs to senders. ISVD's regulation deploys contract and Civil Code Art. 709 tort constructions per path, publishes the damage calculation basis, prevents over-capture via safe harbor, and distributes operational burden via the objection procedure.

Through open-sourcing, the regulation moves beyond ISVD's own defense to function as a propagation template for research institutions, NPOs, and knowledge workers broadly. This is also a self-implementation of ISVD's mission: "to read social issues structurally and generate design-based solutions."

Through accumulation of operational cases, adoption by other organizations, and trial-by-case-law, we aim to verify whether this approach can function as social structural correction for the unsolicited sales-email problem.

This regulation is a draft refined by AI and the Institute, and contains elements whose ultimate legal validity depends on case-law accumulation. To mature this approach socially, continuous critical review and adoption reports from legal practitioners, legal scholars, ethics researchers, sales-domain practitioners, and operators at other organizations are indispensable. With consent, we will list review content, name, and affiliation on this article and the regulation page (critical reviews are also welcomed; we publish with real names and grounds as a rule).

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If you have adopted this regulation/implementation and consent to being listed on the Institute's site and the OSS repository README.

Share adoption

The full regulation suite and reference implementation are released as open source (CC BY 4.0 + MIT), so any organization may, in principle, adopt them independently. However, rather than directly using an AI-drafted regulation as-is, organizations are recommended to adapt it to their own business, operational structure, and legal-risk tolerance, and to obtain a review by their legal counsel. The Institute offers a paid support service that accompanies other organizations through this adoption process.

Note that, in light of Article 72 of the Attorneys Act, the Institute cannot itself act as legal representative in dispute handling (post-invoice response, litigation, payment demand procedures, etc.). The Institute's role is limited to accompanying clients in regulation drafting, implementation integration, and operational design; for dispute representation, the Institute refers clients to attorneys or law firms.

Three options for paid adoption support

From regulation drafting alone to fully integrated implementation and operational design, three tiers are available depending on organization size.

Regulation customization + lawyer review arrangement

JPY 100,000–300,000. Adjusts the regulation draft to your organization's business and arranges a paid review by a partner law firm. Lead time 2–4 weeks.

Regulation drafting

Regulation + implementation integration

JPY 500,000–1,000,000. Includes integration of form consent UI, API validation, and BigQuery / Discord notification, adjusted to your existing site stack. Lead time 4–8 weeks.

With implementation

Organization-wide operation + training + monthly reports

JPY 1,500,000+. Annual-contract package including objection-handling training, monthly violation reports, regulation revision support, and a referral window to lawyers during disputes.

Organization-wide

An initial paid consultation of 30 minutes (JPY 10,000 excl. tax) is available to discuss applicability to your organization and the most suitable support menu. Please contact us via the [contact form](/en/contact?subject=Sales Email Policy adoption inquiry).

Civil Code (Act No. 89 of 1896) — Ministry of Justice (Japan). e-Gov Law Search

Act on Regulation of Transmission of Specified Electronic Mail (Act No. 26 of 2002) — Ministry of Internal Affairs and Communications (Japan). e-Gov Law Search

Act on the Protection of Personal Information (Act No. 57 of 2003) — Personal Information Protection Commission (Japan). e-Gov Law Search

Anti-Spam Consultation Center — Japan Data Communications Association. Japan Data Communications Association

Sales Email Policy (ISVD Regulation) — Institute for Social Vision Design. ISVD

sales-email-policy (Open-Source Implementation) — Naoya Yokota / Correlate Design / ISVD. GitHub