Warmy.io, the AI-powered email deliverability platform that combines warm-up, inbox placement testing, and continuous monitoring in one environment for B2B and B2C senders, has announced an official partnership with Mailvio, an email marketing platform built around relational, permission-based sending, where long-term sender reputation and subscriber retention drive revenue.
The result is a deeply integrated, purpose‑built Mailvio Warm‑Up Tool that embeds Warmy’s deliverability infrastructure directly into the platform, tailored for high‑volume, opt‑in email sending. The partnership addresses a gap that has quietly been costing retention marketers significant revenue: the widespread use of warm-up tools designed for cold outreach on domains utilized for permission-based campaigns.
Why Retention Email Needs Its Own Warm-Up Solution
Bulk retention campaigns and cold email outreach are distinct disciplines. They operate on separate infrastructure, target diverse inbox types, and generate unique engagement signals. Despite this, many marketers reach for the same warm-up tools regardless of which type of sending they do.
This is a costly mistake.
Cold email warm-up pools are engineered around 1-to-1 prospecting patterns: low volumes per recipient, threaded reply chains, and mailbox-to-mailbox engagement signals that mimic personal correspondence.
Retention email, on the other hand, involves high‑volume, broadcast‑style sending to opt-in consumer inboxes (predominantly Gmail, Yahoo, and Hotmail) and must clearly identify itself as such.
When a retention sender routes their domain through a cold email warm‑up pool, they send inbox providers two contradictory reputation signals: in one context, the domain appears to be a one‑to‑one prospecting account, and in another, it appears to be a bulk broadcaster.
Inbox providers resolve this contradiction by defaulting to suspicion. Open rates fall, spam placement rises, and the warm-up service the marketer paid for becomes the cause of the damage.
Warmy.io is one of the few warm-up platforms equipped to handle B2C bulk email properly. Its AI engine, Adeline, simulates human-like interactions across a network of real inboxes, establishing sender reputation in a way that is consistent with how retention messages are actually delivered and received. This distinction is what made Warmy the partner of choice for Mailvio.
Feature comparison: Warmy.io vs. other email warmup integrations
| FEATURE | Warmy | Others |
|---|---|---|
| Dedicated AI for user’s deliverability | ✅ (Adeline AI) | ❌ |
| Unlimited mailboxes can be connected | ✅ | ✅ |
| Maximum warmup emails a day | Millions | < 5,000 |
| Network size | >1M+ active mailboxes | Varies |
| Warm up with clicks | ✅ | ❌ |
| Blacklist monitoring | ✅ (included in the email deliverability test) | Usually comes as an add-on |
| API Access | ✅ | Varies |
| Seed Lists (Gmail, outlook, Yahoo) | ✅ | ❌ |
| Auto-archives warmup emails | ✅ | ❌ |
| Reporting | Advanced | Basic |
| Warmup customization | Advanced (distribution per provider, language, topic, temperature, engagement patterns) | Limited to sending schedules only |
| Multiple language options for warmup emails | ✅ | ❌ |
| Topic warmup | ✅ | ❌ |
| Spintax on the user template | ✅ | Varies |
| Email validation | ✅ | Varies |
| Scalable for teams | ✅ (+ has an agency dashboard) | Robustness varies |
| Email Deliverability Test | ✅ | Varies |
| Dedicated Customer Success Manager | ✅ | ❌ |
| Dedicated deliverability expert for every customer | ✅ | ❌ |
| Email Template Checker inside the platform | ✅ | Varies |
| Email Template Checker (free Chrome extension) | ✅ | ❌ |
| Email Template Checker | ✅ (with Chrome Extension) | Varies |
| Email deliverability A/B testing | ✅ | ❌ |
| SPF Record Generator | ✅ | ❌ |
| DMARC Record Generator | ✅ | ❌ |
| Inbox Academy – free masterclass for email deliverability | ✅ | ❌ |
How Warmy and Mailvio Work Together
The Mailvio Warm-Up Tool is built on Warmy’s deliverability engine, which brings Warmy’s proven expertise in warm-up and reputation-building directly to the Mailvio platform. This goes beyond a simple technical connection. Warmy and Mailvio collaborated to ensure that warm-up traffic is correctly identified as bulk sending. This is a critical requirement for domains used in retention-based email marketing.
Warmy’s infrastructure is put into practice through Mailvio’s DIY calculator, which gathers five key inputs: current domain reputation, warm-up objective, average sending volume, recipient provider mix, and sending mode.
Based on these inputs, the tool produces a complete week-by-week warm-up plan with defined volume targets, daily schedules, and transparent pricing. This is important because mistakes in email warm-up can be costly and difficult to correct. An incorrect configuration can set a sender back months. The Mailvio–Warmy integration mitigates this risk by leveraging Warmy’s deliverability expertise.
What This Partnership Means for Bulk Retention Email Senders
The Warmy–Mailvio integration marks a meaningful step forward for a long‑underserved segment of the email marketing industry.
Retention email, the high‑volume channel behind e‑commerce newsletters, lifecycle campaigns, loyalty programmes, and promotional broadcasts, has long been forced to rely on tools built for a very different purpose.
By combining Warmy.io’s deliverability infrastructure, configured for bulk B2C sending, with native integration in the Mailvio Warm‑Up Tool, retention‑focused senders finally get warm‑up technology that fits how their email programmes actually work.
How Warmy Supports Each Level of Mailvio’s Warm-Up
Mailvio offers warm-up at several levels. Warmy powers some of these levels directly, while others run on methods that Mailvio developed on its own.
Here is where Warmy is used at each stage, and how:
IP warm-up
Mailvio uses Warmy to pre-warm new IP addresses as the platform grows. The process starts by selecting a group of domains and setting them up in Warmy on Mailvio’s internal warm-up pool.
This creates a win-win: the domains get stronger while the IPs get pre-warmed at the same time. Pre-warm-up runs for three months, with volume increasing slowly over that period.
After pre-warm-up, the IPs move out of Warmy and into Mailvio’s best user pool, the excellent pool. Warm-up continues there at an accelerated rate using real email until the IPs are ready and stable.
Once they reach that point, the IPs are moved to whichever pools need them, or they stay in the highest pool.
Domain warm-up and repair
For domain warm-up and repair, Mailvio uses its warm-up plan generator to build a plan for each scenario. A plan starts small and raises email volume using pure warm-up email. At a certain point it begins mixing in real email, then gradually reduces the warm-up email until the goals are met and the plan stops.
What happens next depends on the sender’s real sending stats. If those numbers are strong, Mailvio recommends that the sender simply continue what they are already doing.
If the numbers are weaker, and the nature of the business makes it hard to improve much further, Mailvio strongly recommends moving to a continuous maintenance plan.
Domain maintenance
For maintenance, Mailvio uses Warmy to run a continuous email volume plan made up of warm-up email. The goal is to keep showing ISPs healthy signals per domain: an average of more than 25% opens, more than 1% click-through rate, and a good reply rate each day. Because of this, the volume of warm-up email a sender needs depends on the stats their own campaigns produce.
Conclusion
Retention senders and cold outreach have never needed the same kind of warm-up, yet most have been stuck using one tool for both. Warmy.io and Mailvio set out to fix that. The Mailvio Warm-Up Tool now runs on Warmy’s engine, with its traffic set up to read as the bulk, opt-in sending these programs actually do.
Where it counts, that means real help: getting new IPs ready as Mailvio grows, building and repairing domains through the plan generator, and keeping them healthy over time. Senders get a guided plan with clear volumes, schedules, and pricing instead of guesswork.
For a group that marketing tools have mostly overlooked, it is a warm-up that finally speaks their language.
