---
name: email-subject-line-variants
description: Generates and evaluates diverse email subject-line and preview-text variants against an approved message, audience, brand voice, and channel constraints, with a rationale and test plan. Use for email optimization, subject-line testing, campaign QA, or newsletter subject development.
license: Apache-2.0
metadata:
  adlass.categories: "marketing-content/campaigns-email, marketing-content/brand-tone"
  adlass.industries: ""
  adlass.tags: "subject-lines, email-testing, preview-text, experimentation, copy-qa, email"
  adlass.adaptation: "reference-doc"
  adlass.source: "original"
  adlass.version: "1"
---

# Email subject-line variants

## Purpose

Create a disciplined set of subject lines and preview texts that represent the actual email, cover distinct messaging angles, and can support a clean test.

## Scope

The skill covers angle design, variants, length and tone checks, prohibited language, audience fit, and test design.

**Excluded:** sending tests, choosing winners from absent data, and manipulating recipients with false urgency.

## Data basis

- Final email or campaign brief supplied as an input.
- Audience, brand guide, channel rules and prior results in scope.

## Result

A variant sheet and test-plan brief.

## Quality criteria

- Each variant is accurate, distinct and labelled by angle.
- Preview text adds information rather than repeating the subject.
- Length, tone, claim and compliance rules are checked.
- Test comparisons change one defined variable at a time.

## Instructions

Use the email's strongest reader benefit and preserve its actual offer. Avoid clickbait, unsupported personalization, and urgency not grounded in a real deadline. Treat historical performance as context, not proof of future success.

## Adapt before use

- Add email, audience, brand and channel rules.
- Define length, prohibited terms and test constraints.
- Add prior results and metric definitions.
- Keep source facts, analysis, recommendations, and unresolved questions visibly separate.
- Preserve stable document, section, page, sentence, URL, or row identifiers in every finding.
- Record assumptions about audience, channel, period, approval status, and data coverage.
- Treat missing guidance as an adaptation gap rather than inventing a company rule.
- Prefer a precise, bounded recommendation over a broad generic rewrite.
- Use supplied terminology consistently across the document, sheet, and any derivative copy.
- Do not infer performance, customer behavior, product capability, or market response from wording alone.
- Make every unresolved issue actionable by naming the missing decision, evidence, owner, or source.
- Keep factual claims traceable even when the final copy is concise.
- Recheck that counts, names, dates, and identifiers match across all outputs.
- Mark hypotheses as hypotheses and preserve competing explanations when evidence is mixed.
- Use the stated acceptance criteria as the final completeness check.