A casino sends its weekend promotion to 200,000 players. Half of it lands in spam, a few thousand bounce, and Monday brings a complaint from a player who never opted in to casino emails. The offer was fine. The email programme wasn’t.
Since 2024 the big mailbox providers have tightened their rules for bulk senders, and gambling regulators have tightened theirs on consent. This article covers both, with practical tips for getting promotional emails delivered and keeping them lawful. For general campaign ideas, see our older guide to promoting an iGaming business by email.
Tip 1: Meet the Bulk Sender Rules
Gmail and Yahoo introduced requirements for bulk senders in February 2024, and Microsoft followed for Outlook.com, Hotmail and Live addresses in May 2025. Most online casinos count as bulk senders, which Google defines as sending around 5,000 or more messages a day to personal Gmail accounts.
| Requirement | Gmail | Yahoo | Outlook.com |
|---|---|---|---|
| SPF and DKIM authentication | Required | Required | Required |
| DMARC policy (at least p=none), aligned | Required | Required | Required |
| Unsubscribe | One-click required for marketing mail, honoured within 2 days | Unsubscribe header required, one-click strongly recommended, honoured within 2 days | Recommended |
| Spam complaint rate | Keep below 0.3%, ideally under 0.1% | Keep below 0.3% | Not specified |
Microsoft began rejecting non-compliant mail from high-volume senders on 5 May 2025. Gmail tightened enforcement again from November 2025, moving from warnings to temporary and permanent rejections. If your authentication isn’t set up correctly, promotions may simply not arrive.
Tip 2: Get Consent Right for Each Market
In the UK, email marketing to individuals generally needs consent under the Privacy and Electronic Communications Regulations. There is a soft opt-in for existing customers buying similar products, but gambling operators face a stricter rule on top.
Since 1 May 2025, UK Gambling Commission licensees must let customers opt in to direct marketing separately for each product (betting, casino, bingo) and each channel (email, SMS, phone). Every option is off by default, and existing customers had to confirm their choices at their first login after the rule started. A player who opted in to sports emails cannot be sent casino promotions.
Other markets have their own limits. In Ontario, advertising bonuses and inducements is banned except on the operator’s own site and in direct marketing sent after the player has actively consented. In the Netherlands, online gambling advertising must reach an audience that is at least 95% aged 24 or over.
Tip 3: Make Unsubscribing Easy
It sounds backwards, but an easy exit protects your sender reputation. Players who can’t find the unsubscribe link press the spam button instead, and spam complaints are what mailbox providers watch most closely. Add the one-click unsubscribe header, keep a visible link in the footer and honour requests within two days.
Tip 4: Segment by Behaviour, Not Just by Country
Send sports promotions to players who bet on sports and casino offers to players who play casino, and only on the channels they chose. Behaviour-based segments also lower complaints, because the email is relevant. Our online casino CRM playbook shows how to build these journeys.
Tip 5: Check Every Offer Against the Bonus Rules
An email is often the first place a bonus appears, so it must follow the rules of the player’s market. In Great Britain, wagering requirements have been capped at 10 times since 19 January 2026, and promotions that mix products, such as a free bet that unlocks free spins, are banned. In the Netherlands, bonuses linked to losses are not allowed.
Tip 6: Watch Your List Hygiene
Remove hard bounces immediately. Stop mailing players who haven’t opened anything for months, or send them a short re-permission email first. Never buy lists. Purchased addresses don’t have valid consent and are full of spam traps.
Tip 7: Suppress Players Who Should Not Be Contacted
Self-excluded players, players in a cooling-off period and those flagged by safer gambling checks should be removed from every send automatically. Build this into the sending platform rather than relying on someone to export a list before each campaign.
Tip 8: Measure What Matters
Opens are less reliable than they used to be because of privacy features in mail apps. Track delivered rate, clicks, deposits from email, unsubscribes and spam complaints. Google Postmaster Tools shows your spam rate and domain reputation for Gmail.
FAQ
Do I need DMARC to send casino promotions?
If you send in bulk to Gmail, Yahoo or Outlook.com users, yes. All three require SPF, DKIM and a DMARC policy for high-volume senders.
Can I email UK players who signed up before May 2025?
Only for the products and channels they confirmed. Existing customers had to make their choices at their first login after the rule started.
What spam complaint rate is too high?
Gmail and Yahoo both say to stay below 0.3%. Gmail recommends keeping it under 0.1%.
Good casino email in 2026 starts before the creative: authenticated domains, real consent per product and channel, easy unsubscribes and offers that follow the bonus rules. Get those right and the campaigns can do their job.
Industry events are where ideas turn into partnerships, and Gamingsoft is a consistent presence at the most important conferences on the global iGaming calendar. We attend these gatherings to stay close to the operators, developers, and regulators shaping the industry. Many of our strongest partnerships began with a conversation at an event. Our team is always ready to discuss game aggregation deals, market challenges, or anything else on your mind. Visit gamingsoft.com and connect with our business development team today.
