What is a promotional email?

A promotional email markets a product, service, or offer to subscribers. Distinct from transactional email (order confirmations, receipts), promotional email is commercial in nature and subject to CAN-SPAM, GDPR, and other marketing email regulations. Requires explicit opt-in in most jurisdictions and includes physical address and unsubscribe link.

How often should I send promotional emails?

1-4 promotional emails per month for most B2C, 1-2 for B2B, varying by industry and engagement levels. Ecommerce during sale periods (Black Friday, holidays) can spike to daily without damage if recipients expect it. Avoid sending promos to subscribers who haven't engaged in 90+ days — they'll mark as spam.

Do promotional emails go to spam?

Promotional emails go to spam when sender reputation is low, authentication fails, complaint rates are high, or content patterns trip filters. Most modern senders with proper SPF/DKIM/DMARC and a clean engaged list land promos in inbox or Gmail Promotions tab. Promotions tab isn't spam — it's the expected placement for promotional content.

How to Write Promotional Emails (Without Tripping Filters)

Q: How to write a marketing email?

Marketing emails work when they're written to one type of recipient with one clear message and one CTA. Structure: specific subject line under 60 chars → opening that matches the subject → body explaining the value → single primary CTA → footer. Skip vague enthusiasm, write like you'd email a colleague, and send to people who actually want what you're selling.

Q: How to write promotional emails?

Promotional emails need: clear value in the subject ('20% off through Sunday' beats 'Big news!'), opening that delivers on the subject promise, body that explains the offer and creates real (not fake) urgency, single CTA button, and visible unsubscribe. Send to engaged segments — promos to non-engaged subscribers tank deliverability.

Promotional emails are where deliverability and copywriting collide. You're trying to drive a sale, which means urgency language, sale prices, calls to action — content patterns that filters watch for. Done well, your promo lands in the inbox or Promotions tab and converts. Done badly, it goes to spam and burns reputation for your future sends.

The cluster around how to write a marketing email, how to write promotional emails, and promotional emails covers the basic structure plus the deliverability traps. This guide is sender-side — what writing patterns work, what trips filters, and how to test before launching.

The Promotional Email Structure

SUBJECT: [Specific offer + duration]
PREHEADER: [Complements the subject, adds detail]

[OPTIONAL HEADER — small logo, 150px wide]

[OPENING — 1-2 sentences stating the offer]

[BODY — 100-200 words explaining]
— What's on offer
— Why now (real urgency)
— Who it's for

[CTA BUTTON]

[OPTIONAL secondary content]
  — Featured products
  — Customer testimonial
  — FAQ link

[FOOTER]
  Brand name
  Physical address
  Unsubscribe | Manage preferences

Single column. 600px wide. Mobile-first. Under 102KB HTML to avoid Gmail clipping. See email layout design.

Subject Line for Promotions

Specific beats clever. The promotional subject lines that consistently outperform:

Good:

"20% off everything through Sunday"
"Your code expires in 24 hours"
"Free shipping on orders over $50"
"New Pro plan — first month $1"
"Last day: 50% off [Specific Product]"

Bad:

"Amazing news!"
"You won't believe this offer"
"Don't miss out on this exclusive opportunity!!!"
"OPEN NOW for a special surprise"
"Hi [Name], we miss you"

The bad examples are vague, hype-led, and signal phishing-adjacent patterns. The good ones are specific facts.

Length: 30-60 characters for mobile compatibility. Test with your audience. See email subject lines that get opened.

Preheader Strategy

Always set explicitly. Don't let the ESP auto-generate from "View this email in your browser."

Good preheader pairs:

Subject: "20% off everything through Sunday"
Preheader: "Code SAVE20 at checkout. Shop bestsellers →"

The preheader continues the subject's promise with specifics or a CTA hint.

Opening Line

The opening matters because mobile preview shows ~100 characters of body alongside the subject. First sentence is the third deciding factor in opens.

Bad opening: "Hi [Name], we're excited to share some amazing news with you today!"

Good opening: "20% off everything through Sunday — use code SAVE20 at checkout."

Get to the point. The recipient opened your email because the subject promised something. Deliver the something immediately.

Body Content

100-300 words for most promotional emails. Newsletter-style promos can run longer if structured for scanning.

Effective body patterns:

Direct Value Proposition

20% off everything through Sunday.

Use code SAVE20 at checkout.

Free shipping on orders over $50.

Sale ends Sunday at midnight Pacific.

[Shop bestsellers]

Minimal copy. The product page does the heavy lifting.

Social Proof + Offer

The [Product] has shipped to 50,000+ customers
with a 4.8 average rating.

This week only: 25% off all variants.

Use code REVIEWS25 at checkout.

[Shop the [Product] line]

Validates the buy decision before the offer.

Story + Offer

We just released the 2026 version of our most-requested feature.

[Brief 2-3 sentence description]

Existing customers get it free in their next billing cycle.
New customers can get the Pro plan with the new feature
for $1 first month.

[Start the trial]

Story-led for product launches and feature announcements.

CTAs

One primary CTA per email. Button styling:

44px tall minimum (mobile tap target)
8-16px padding
Contrasting color (button against background)
Specific text ("Shop the sale" not "Click here")
Above the fold on mobile (within first 480px height)

Secondary content can have its own CTAs in body, but only one should dominate visually.

What Triggers Filters

The patterns that get promotional emails filtered:

Image-only emails — no text content for filters to read
ALL CAPS subject or body — signals spam pattern
Excessive punctuation — !!! and $$$ trigger rules
URL shorteners — bit.ly and similar are spam-associated
Many links — 10+ links in a marketing email is risky
Hidden text — white-on-white text for keyword stuffing (still common in old templates)
Mismatched From and Reply-To — phishing signal
Broken HTML — malformed tags, missing closing elements
Phishing-template language — "verify your account," "unusual activity detected"

See spam trigger words 2026 for the broader content discussion. In 2026, sender reputation matters more than word choice — but content patterns can still trip filters if they match known spam templates.

Practitioner note: I see senders worry obsessively about "spam trigger words" while their actual deliverability problem is sending promos to a list that's 60% non-engaged. Word choice contributes ~5% of filtering decisions. List health and authentication contribute the other 95%. Fix engagement and authentication first.

Send to the Right Recipients

The biggest determinant of promotional email performance:

Segment	Open rate	Conversion
Engaged (opened in last 30 days)	35-50%	3-8%
Recent (30-90 days)	20-30%	1-3%
Inactive (90-180 days)	8-15%	0.5-1%
Dormant (180+ days)	3-8%	<0.5%
Cold (no engagement history)	5-12%	<0.3%

Sending the same promo to engaged and dormant segments produces aggregate "okay" results that mask the truth: the engaged segment performs great and the dormant segment hurts your reputation.

Segment by engagement and send promos primarily to engaged. See engagement-based sending — or apply your ESP's engagement-based segments.

Frequency

Promotional email frequency tolerances vary:

B2C ecommerce normal: 2-4 promos per week
B2C ecommerce sale periods: daily can work
B2B SaaS: 1-2 per month, more if user is engaged
Newsletter audiences: 1 promo per 3-4 newsletter sends
Consumer subscription services: 1-3 per month

Stay within recipient tolerance. Frequency mismatch generates complaints, which damages deliverability.

A/B Testing Promos

Test variables with statistical significance:

Subject line (most impactful single variable to test)
From name (Brand vs Person at Brand)
Send time (morning vs evening for your audience)
CTA copy ("Shop sale" vs "Get 20% off")
Body length (short vs long for the same offer)

Don't test on small samples — under 1000 per variant is noise.

Testing Before Send

For every promotional campaign:

Render check across Gmail, Outlook desktop, iOS Mail
Mail-Tester score (target 8+/10)
Mobile preview on actual mobile
Click every link to verify destinations
Test unsubscribe link
Read aloud — does it sound human?

See email testing services.

What I Recommend

For a promo email that converts and reaches the inbox:

Specific subject under 60 chars
Preheader complements subject
Single message, single CTA
100-200 word body
Mobile-first single-column layout
Send to engaged segments primarily
Set up real urgency, not fake
Authenticate properly (SPF/DKIM/DMARC)
Test before sending

If you need help auditing promotional email programs for conversion AND deliverability, book a consultation. I work with ecommerce and SaaS teams on promotional sequence design and the deliverability infrastructure underneath.

Sources

v1.0 · May 2026