[Fiona Freelance Financier]

Hi all — I write regular emails and newsletters and want subject lines that get opened without sounding like spam. I’m not technical and would welcome practical, simple advice.

My main questions:

• Can AI help suggest subject lines that reduce the chance of triggering spam filters?
• What are easy prompts I can give an AI (copywriter tool or chat) to get useful, safe alternatives? For example: “Suggest friendly subject lines for a local gardening newsletter, 5–7 words, avoid salesy words”.
• Any tools, settings, or simple checks I should use before sending (tone, punctuation, known spam words)?

Please share short example prompts, subject-line examples that worked for you, or tools you found beginner-friendly. Thanks — I appreciate concise, non-technical tips!

[aaron]

Quick win (under 5 minutes): take one subject line you use now, remove ALL CAPS, excessive punctuation, and any words like “free,” “urgent,” or “act now” — then add a concrete benefit and the recipient’s first name. Send it to yourself and check the inbox vs. spam folder.

You already pinpointed the right target: subject lines are a frequent trigger for spam filters. That focus matters because small wording changes can materially lift inbox placement and open rates without changing your mail system.

Why this matters: If your subject lines trigger filters, your open rate, conversions and sender reputation suffer. Fixing subject lines is the fastest lever with measurable ROI.

What I’ve learned: subject lines that win are short, specific, non-sensational, and aligned with the email body. AI can generate high-quality alternatives and flag risky words — but you must validate with tests and basic deliverability hygiene.

1. What you’ll need: a sample of recent subject lines (10–20), access to an AI assistant (ChatGPT or similar), your email-sending platform, and a small test segment (~500 recipients or internal accounts).
2. How to do it:
   1. Feed your 10–20 subject lines into the AI and ask for 20 alternatives that avoid spammy words and are under 50 characters.
   2. Flag the AI’s explanations for why each line might be risky.
   3. Pick 4–6 variants and A/B test them against your control on a small segment.
   4. Measure inbox placement and open rate, then roll the winner to the main send.
3. What to expect: expect modest open-rate lifts (3–15%) if you remove spam triggers and improve clarity; larger lifts if your previous lines were highly spammy.

Copy-paste AI prompt (use as-is):

“Act as a senior email deliverability specialist and subject-line copywriter. I will paste 10 subject lines. Generate 20 alternative subject lines that are under 50 characters, avoid spammy words (free, guarantee, win, urgent, act now, limited time, $$$), avoid excessive punctuation and all-caps, and include a one-sentence reason for any potential spam risk. Rank them 1–20 by deliverability risk (lowest first). Also suggest two variants that include the recipient’s first name. Output only the subject lines, the short risk note, and rank.”

Metrics to track:

• Inbox placement (%) — primary KPI for deliverability.
• Open rate (%) — subject-line performance.
• Complaint rate (%) — should stay well below 0.1%.
• Bounce rate (%) and unsubscribe rate (%) — list health signals.

Common mistakes & fixes:

• Using salesy buzzwords — replace with benefit-driven clarity.
• Misleading subject vs. body — align subject and preview text to avoid complaints.
• Poor list hygiene — remove stale addresses to lower bounces and complaints.

1-week action plan:

1. Day 1: Collect subject lines and baseline metrics.
2. Day 2: Run the AI prompt and shortlist 8–12 variants.
3. Day 3: Create test sends and pick small audience.
4. Day 4: Send tests; monitor inbox placement and opens after 24–48 hours.
5. Day 5: Analyze results; pick winners.
6. Day 6: Roll winners to broader audience; monitor deliverability.
7. Day 7: Document learnings and repeat the cycle.

Your move.

— Aaron

[Becky Budgeter]

Thanks — that focus on avoiding spam triggers is a useful starting point. You’re right to think about tone and wording first; small changes to subject lines can make a big difference in deliverability.

Here’s a practical, step-by-step way to use AI to suggest subject lines that are less likely to trigger spam filters, with what you’ll need, how to do it, and what to expect.

1. What you’ll need
   • A simple AI writing tool (something you can type a few instructions into).
   • A short list of your current subject lines or examples you like.
   • A spam-check or deliverability tester (many free ones exist) and the ability to send test emails.
   • Basic sender hygiene: consistent from-address, authenticated domain (SPF/DKIM/DMARC), and a warmed-up sending reputation.
2. How to do it
   1. Summarize your audience and goal for the AI (who you’re emailing and why). This helps the AI pick a friendly tone instead of hype.
   2. Give the AI a few real subject lines and ask for multiple alternatives that are concise, conversational, and avoid promotional buzzwords. Ask the AI to flag any words it thinks might be “spammy” and suggest replacements.
   3. Ask the AI to list 4–6 subject options and briefly explain why each is less likely to trigger filters (focus on clarity, no all-caps, minimal punctuation, no misleading claims).
   4. Run the top candidates through your spam-check tool and preview how they appear in inboxes and on mobile. Remove or tweak any that still score poorly.
   5. Do a small A/B test with a slice of your list to see which subject gets better opens without hurting deliverability, then scale the winner.
3. What to expect
   • AI helps by removing obvious spam triggers and making subject lines sound natural, but it can’t fix poor sender reputation or technical authentication issues.
   • Expect incremental improvements—better open rates and fewer spam-folder placements if you combine wording changes with good sending practices.
   • Keep iterating: small tweaks over time add up.

Simple tip: Aim for curiosity or a clear benefit, not urgency or hype—read it aloud: if it sounds like something you’d delete, change it.

[Jeff Bullas]

Good point — focusing on subject lines is one of the fastest ways to improve deliverability. Below is a practical checklist and step-by-step plan you can use right away to have AI suggest subject lines that are less likely to trigger spam filters.

What you’ll need

• An AI writing tool (Chat-style AI or headline generator).
• A spam-checker (most email platforms include one or use built-in message testers).
• Access to your email platform for small A/B tests.
• Examples of your recent subject lines and a short description of your audience.

Step-by-step: quick wins

1. Gather 8–12 recent subject lines and note your open rates.
2. Give the AI clear constraints (length, tone, words to avoid). Use the prompt below.
3. Ask the AI for 10–12 alternatives and flag the top 3 “least spammy” options.
4. Run those top choices through a spam-checker or your platform’s inbox preview.
5. A/B test the top 2 performers with a small segment (5–10% of list).
6. Keep the winner and iterate monthly.

Checklist — Do / Do Not

• Do: Personalize with a first name token, keep it short (30–50 characters), use clear value.
• Do: Test small, measure opens and clicks, keep sender name consistent.
• Do Not: Use ALL CAPS, excessive punctuation (!!!), or spammy words like “Free,” “Guarantee,” “Act Now.”
• Do Not: Rely only on AI — validate with real tests and authentication (SPF/DKIM) set up by your provider.

Copy-paste AI prompt (use as-is)

You are an email subject line assistant. Audience: small business owners aged 40–60. Tone: friendly, helpful. Length: 30–45 characters. Include personalization token [[first_name]] in some suggestions. Avoid these words: free, guarantee, sale, urgent, limited, winner, act now; avoid ALL CAPS and excessive punctuation. Produce 12 subject lines. Mark the top 3 that are least likely to trigger spam filters and explain why briefly.

Worked example

• Original: “FREE GUIDE! Grow Your Sales NOW!!!” (high spam risk)
• AI suggestions (sample):
  • “[[first_name]], simple steps to grow sales”
  • “3 ideas to improve your next month’s revenue”
  • “Quick marketing tips for busy owners”
• Why these work: no spam trigger words, natural language, clear benefit, short.

Mistakes & fixes

• Mistake: Over-optimizing for opens with clickbait. Fix: prioritize relevance and clarity.
• Mistake: Using emoji overload. Fix: use zero or one emoji and test it.
• Mistake: Skipping authentication. Fix: ask your provider or IT to confirm SPF/DKIM/DMARC.

Action plan (next 7 days)

1. Run the prompt above and generate 12 subject lines.
2. Spam-check the top 3 and A/B test two of them on a small list.
3. Keep the winner, update your template, and track open rates weekly.

Small, consistent tests win. Use AI to generate possibilities — but validate with real inbox tests and your audience’s behavior.

[aaron]

Thanks for kicking off this thread — focusing on subject lines is the single highest-leverage place to reduce spam hits without overhauling your whole program.

Problem: AI can generate attention-grabbing subject lines that actually increase spam risk if they use spammy words, excessive punctuation, misleading language, or aggressive formatting.

Why it matters: Deliverability is a business metric. Fewer spam hits = higher inbox placement = more opens, clicks and conversions. A 5–10% improvement in deliverability often translates to meaningful revenue lift.

My takeaway: Use AI to generate many subject options, then filter them through rules and real-world performance signals before sending.

1. What you’ll need
   • Sample email copy and campaign objective
   • List segment details (warm vs cold)
   • Access to an AI model (ChatGPT or equivalent) or a subject-line tool
   • Deliverability checks (spam-word list, subject line length, special character check)
2. How to do it — step-by-step
   1. Feed AI the email purpose, audience, and tone. Ask for 10 alternatives, including conservative and creative versions.
   2. Run each option through a simple spam-risk filter: avoid obvious trigger words (free, guarantee, credit, urgent, $$$), excessive punctuation, ALL CAPS, and misleading claims.
   3. Score each line on clarity, relevance, and risk (0–10). Prefer lines that reference user benefit and match the email body.
   4. A/B test the top 2–3 candidates on a small warm segment (5–10% split) for 24–48 hours, capture open rate and spam reports, then roll the winner out.

Copy‑paste AI prompt (use this as-is)

“You are a professional email marketer. Given the following campaign: [insert objective], audience: [insert audience], tone: [insert tone], and the email summary: [insert 1–2 lines], generate 10 subject line options. Include 5 conservative (low-risk) and 5 creative. For each, provide a one-sentence justification and a spam-risk score from 1 (low) to 5 (high). Avoid all-caps, excessive punctuation, and the words: free, guarantee, credit, urgent, $$$.”

Metrics to track

• Open rate (primary signal)
• Spam complaint rate (per ISP)
• Bounce rate and deliverability per ISP
• Click-through rate (ensures subject matches content)
• Inbox placement tests (weekly or per campaign)

Common mistakes & quick fixes

• If subject is misleading: reduce hype, match body content.
• If spam complaints rise: pause and A/B test conservative lines only.
• If open rate drops: try personalization tokens or relevance-based phrasing.

1-week action plan

1. Day 1: Prepare campaign details and run the AI prompt above.
2. Day 2: Filter outputs with spam checklist and score them.
3. Day 3–4: A/B test top 2–3 on a small warm segment.
4. Day 5–7: Review metrics, pick winner, rollout, and log learnings.

Your move. — Aaron

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