Email marketing in gambling: how not to get into spam

Gambling is a "sensitive" category for postal providers. The same mistakes (dirty databases, aggressive offers, lack of authentication) turn even good content into spam. The good news: deliverability is a system. Below - what to do so that letters get into the "Inbox," and complaints and blocking do not kill the reputation.

💡 Important: observe local laws (GDPR, CAN-SPAM, CASL, etc.) and site rules. In communications - Responsible Gaming, age restrictions, no promises of winnings.

1) 4 pillars of deliverability (in order of importance)

1. Consent and involvement of addressees - double opt-in, understandable offer, high engagement.

2. Domain/IP reputation - warm-up, stable volume, no complaints and spam tags.

3. Technical authentication - SPF, DKIM, DMARC (policy not weaker than'p = quarantine'after stabilization), optional BIMI.

4. Content and UX signals - honest subject, clean layout, visible one-click, no "heavy" triggers.

2) Infrastructure and settings: make the "skeleton" reliable

Separate domain/subdomain for mailings: 'mail. example. com 'or' news. example. com`. Marketing and transaction letters - on different subdomains and IP.

SPF: include only the sources you want, avoid '+ all'.

DKIM: key length 2048 bit, unique selectors for ESP/channels.

DMARC: start with'p = none '(monitoring), then → 'quarantine' → 'reject'after stabilization. Collect RUA/RUF reports.

BIMI (if possible): verified logo increases trust (strict DMARC-policy required).

List-Unsubscribe: Add mailto and HTTPS + header 'List-Unsubscribe-Post: List-Unsubscribe = One-Click'.

Separate IP (if the volumes are large): white "marketing" and separate "transaction."

Feedback: connect complaints (feedback loops) from available providers and automatically cross out complainants.

3) Warming up the domain and IP: how to start without locks

Week 1-2:

Send only to active subscribers of the last 30-60 days, in small batches.
Targets: high open/click, <0. 1% complaints, low bounce.

Week 3-4:

Expand segments, but keep even slots (morning/day), avoiding "sawing" volumes.

After warming up:

Any jump + 50-100% volume = new mini-warm-up.
Freezing on complaints: stop the problem segment, clean up the base, restore reputation on the "core" of assets.

4) Collection and hygiene of the base: without this deliverability does not happen

Only voluntary subscription: double opt-in, understandable checkbox, consent log.

No purchased/" drain" bases. This is a direct path to spam traps.

Regular cleaning:

Hard bounce - cross out right away.
Soft bounce - 3-5 consecutive quarantine →.
Inactive: sunset policy. For example, 90 days without opening → win-back chain → sleep → deletion.
Input validation: format hints, MX verification, protection against one-time domains.
Preference Center: frequency/themes to avoid losing subscribers due to irrelevance.

5) Content and Compliance for iGaming

Subject/pre-header: informative, no clickbait. Don't disguise the promo as an "important message."

Tone: neutral expert, without promises of winnings and "easy money."

Responsible game: age mark, link to Responsible/restrictions.

Letter-body:

clear offer + "What's new/why now";
bonus terms table (if any): vager, term, contribution of games, max cashout, optional GEO;
visible "Unsubscribe" and/or "Adjust frequency" button;
physical address/contacts of the sender.
Layout: adaptive, do not overload with pictures, ALT texts, text-picture ≥ 60/40.
Filter triggers: Avoid "instantly everything," "warranty," "no risk." Write ranges and factors ("usually 15 min - 24 h after KYC").

6) Frequency and segmentation: treating the cause, not the symptom

Frequency: start from 1-2/week and adjust according to engagement. Increase complaints/unsubscriptions → cut frequency or suggest "once a month."

Slices: GEO/language, activation age, type of interest (bonuses, payments, slots/providers, Responsible/guides).

Behavioral logic: separate onboarding chains, win-back, reminder of unfinished action (without pressure).

7) Transactional vs promo: Share and manage risk

Transaction letters (confirmations, KYC, notifications) - the most reliable infrastructure, their own subdomain and IP, "clean" layout, minimum marketing.

Promo - a separate subdomain/IP, piloted on active segments, strict base hygiene.

8) Monitoring and alerts: what to watch every shipment

Pre-sender: presence of SPF/DKIM/DMARC, correct From/Reply-To, presence of List-Unsubscribe.

After sending:

delivery rate, hard/soft bounces;
open/click, complaints (complaint rate);
domain slices (gmail/outlook/yahoo/local).

Alarm thresholds:

complaints> 0. 1–0. 3% - campaign stop and audit;
hard bounces >0. 5-1% - problems with the base or infrastructure;
a sharp drop in open/click on one domain - local filtering.

9) Problem diagnosis: step-by-step triage

1. Falls open at one provider? Check reputation/speed/volume, allocate traffic to a separate pool, cut frequency.

2. High bons? Stop the entire segment, validation, remove dirty sources.

3. Are complaints growing? Check subject/frequency/relevance, unsubscribe/preferences, exclude "cold" lists.

4. Emails in "Promo/Spam" for a specific domain? Test alternative content, reduce the volume, temporarily switch some of the traffic to the most involved segment.

10) Checklist before each mailing

Base: double opt-in, fresh segments, excluded complainers/sleepers
Authentication: SPF/DKIM OK, DMARC enabled
Headers: correct From/Reply-To, added List-Unsubscribe (one-click)
Content: honest subject/pre-trader, condition table (if about bonuses), Responsible/18 +
Layout: †, ALT texts, text/pictures ≥ 60/40, image weights optimized
Frequency: Met for segment, A/B options ready
Tests: sending to seed list and to real team boxes (different providers)
Logs: domain slices included, alerts to complaints/bons

11) Letter templates (fragments)

Subject (ethical):

"All bonus terms - on one page"
"Conclusion: usually 15 min - 24 h after KYC - details in the letter"
"Demo a new release - try it without registering"

Preheder:

"Vager, deadlines, games contribution - a simple table inside"
"The methods and timing of withdrawal depend on the method - we explain"

Footer (minimum):

Responsible Gaming/Age Disclaimer
Visible one-click and preference center
Postal address and support contacts

12) 30/60/90 day plan

0-30 days - foundation

Put mailings on a subdomain, configure SPF/DKIM/DMARC, List-Unsubscribe (one-click).

Base audit: remove bounces, complainants, implement double opt-in and sunset policy.

Warming up on the active core, seed tests, first A/B (subject/frequency).

31-60 days - stabilization

Enter preference center, separate transactional/promo channels.

Segmentation by engagement and GEO, send calendar, win-back for sleepers.

Reporting on domain cuts, alerts on complaints/bons.

61-90 days - scale

BIMI (when ready), tightening DMARC to 'quarantine/reject'.

Trigger chains (onboarding, resembling, win-back) with persegmentation.

Incident regulations: who does what with the growth of complaints/bonuses/filtering.

13) Frequent bugs and quick fixes

Purchased bases/old lists. → Immediate stop, cleaning, only double opt-in.

No one-click unsubscribe. → Add headers and a transparent link at the top/bottom of the letter.

Clickbait subject. → Informative topics + regular A/B tests.

Single IP for everything. → Separate transactional and promo, if possible - different pools.

Volume jumps. → Smooth schedule, mini-warm-up with growth.

Too frequent letters to everyone. → Preference center, interest and engagement segments.

Ignoring complaints/bonuses. → Auto-crossing out complainants, quarantine soft bounce, removing hard bounce.

14) Mini-FAQ

Is double opt-in needed in gambling?

Yes I did. It reduces complaints/spam traps and increases reputation.

Is it possible to "warm" the reputation with transaction letters and then send a promo?

Not worth it. Separate domains/IP and signals. Transactional is sacred.

Why do letters sometimes get into "Promo" from large providers?

This is a normal scenario for marketing. Your task is a stable reputation, relevance, an honest subject and a clean base, so as not to slip into Spam.

Deliverability is not filter magic, but discipline: pure consent, competent authentication, smooth warm-up, honest content and transparent unsubscribe. In gambling, this is doubly critical: by complying with Responsible Gaming and legal requirements, you retain your reputation and income. Build the system in steps - and mailings will stably get into the "Inbox," bring revenue and not undermine the brand.