The Newsletter Ad Stack
Built for Email
MailAdx gives newsletter operators a complete ad monetisation platform — supply-side inventory management, demand-side campaigns, and a real-time ad server that runs the waterfall when subscribers open your email.
Trusted by 150+ newsletter operators
<!-- Paste once in your ESP template -->
<a href="https://mailadx.com/api/v1/serving/click?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}"
target="_blank" rel="noopener">
<img src="https://mailadx.com/api/v1/serving/display?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}&w=728&h=90"
width="728" height="90" alt="" />
</a>
# Auction runs when subscriber opens — <5msToday
+12.4%Fill rate — target 95%
Works with your ESP — 22+ integrations
22+
ESPs integrated
Plug in without code changes
<5ms
Ad decision latency
Real-time at open time
1
Unified platform
SSP + DSP + Ad Server
0
JavaScript tags
Email-native image URLs
Platform
One platform, every role
Publishers, advertisers, and operations teams each get purpose-built tools — unified under a single account.
Monetise every newsletter send
MailAdx SSP gives you a complete inventory management layer — define ad placements, set price floors, control which advertisers appear, and watch revenue flow automatically at every send.
- Drag-and-drop ad unit builder with live preview
- Per-placement floor prices and category blocks
- Publisher portal with real-time fill and revenue
Ad Placement Performance
Reach engaged newsletter readers
The MailAdx DSP lets you launch, target, and optimise email ad campaigns with precision — audience segments, creative variants, daily budget controls, and transparent delivery reporting.
- Audience targeting by topic, geo, and list size
- Multiple creative formats: image, text, sponsored sections
- Realtime campaign dashboards with impression data
Campaign Overview
Fintech Readers — Q1
Startup Founders
Marketing Pros
Open-time intelligence, not stale send-time ads
When a subscriber opens your email, MailAdx runs the full waterfall in real time via a dynamic image URL — fresh pacing, live caps, and accurate impressions for every open.
- Sub-5ms waterfall at open time via display URL
- OpenRTB-compatible waterfall and direct sold prioritisation
- Fallback and house ad support built in
// open-time waterfall
1. Direct sold deals
2. Private marketplace
3. OpenRTB open exchange
4. House / fallback ad
Winner: Direct deal #D-4821 · 7ms
How it works
From setup to first ad in one afternoon
MailAdx is designed to fit into your existing workflow, not replace it.
Connect your ESP
Add an email-hash merge field and paste the MailAdx ad tag into Mailchimp, Klaviyo, Beehiiv, or any ESP template. No webhooks or per-subscriber API loops required.
Define placements & inventory
Use the Publisher Portal to create ad placements within your newsletter template. Set price floors, block lists, and creative specifications per slot.
Load demand
Add advertisers directly via the DSP dashboard, connect to OpenRTB exchanges, or negotiate private marketplace deals. MailAdx manages prioritisation automatically.
Open — ad decisions in <5ms
When a subscriber opens your email, their client fetches the ad image URL. MailAdx runs the waterfall in real time and returns the winning creative — impressions only count for genuine opens.
<!-- Step 4: Paste ad tag — decision at open time -->
<a href="https://mailadx.com/api/v1/serving/click?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}"
target="_blank">
<img src="https://mailadx.com/api/v1/serving/display?pub=YOUR_PUB&pk=header&eh={{EMAIL_SHA256}}&w=728&h=90"
width="728" height="90" alt="" />
</a>
// {{EMAIL_SHA256}} = ESP merge tag for subscriber hashWho it's for
Built for every role in the email ad ecosystem
Turn your newsletter list into a revenue channel
Whether you have 5,000 subscribers or 5 million, MailAdx provides the infrastructure to sell ads directly to advertisers, connect to programmatic demand, and keep total control over what appears in your inbox.
- Self-service ad unit builder — define placements in minutes
- Price floors and category block lists per placement
- Private deals with named advertisers
- Publisher portal: real-time fill rate and revenue dashboards
- Automatic invoicing and payment disbursement
- Dedicated support and onboarding team
Revenue breakdown — this month
Customer stories
Teams who ship better with MailAdx
“We were manually inserting sponsor links for two years. MailAdx replaced our entire workflow — placement management, fill rate tracking, payment collection — in one week. Revenue per send is up 34%.”
Sarah Chen
Founder, TechWeekly Newsletter
“The open-time ad tag is exactly what I needed. We paste it once in our template and MailAdx runs the auction when subscribers open — under 5ms, no JavaScript, no deliverability impact. It just works.”
Marcus Thompson
Head of Engineering, Fintech Focus Media
“As an advertiser managing 15 newsletter campaigns, having one dashboard with consolidated reporting across all publishers is a game-changer. CPCs are down 22% compared to our social spend.”
Priya Patel
VP of Growth, SaaSConnect Inc.
Start monetising your newsletter today
Join 150+ newsletter operators using MailAdx to run a full ad stack — without the complexity.