Introduction
If you're scaling cold email outreach, you've probably come across both Winnr and Maildoso as options for SMTP infrastructure. Both platforms promise easy mailbox setup, DNS authentication, and volume-ready infrastructure — but the similarities end quickly once you dig into pricing, reliability track record, and actual features.
Maildoso has been around for a while, but its history is marked by recurring reliability issues, user complaints about inconsistent deliverability, service disruptions, and pricing that's significantly higher than newer alternatives. This is an honest, head-to-head comparison based on publicly available pricing, documented user experiences on G2 and Reddit, and hands-on testing. We'll cover where each platform stands and why more cold emailers are making the switch to Winnr.
Pricing: Winnr Is 40–55% Cheaper
Pricing is where the gap between Winnr and Maildoso is most dramatic. At every tier, Winnr delivers significantly more value per dollar.
The numbers at 50 mailboxes
- Maildoso: $100/mo for 32 mailboxes on their Starter plan. To reach 50 mailboxes, you need the Pro plan — pushing cost to ~$155/mo. That's roughly $3.10 per mailbox.
- Winnr: $69/mo for 50 mailboxes on the Growth plan. That's $1.38 per mailbox — 55% cheaper than Maildoso.
Winnr: $1.38/mailbox (50 accounts at $69/mo) — Maildoso: ~$3.10/mailbox (50 accounts at ~$155/mo). That's a 55% savings with Winnr at 50 mailboxes.
Billing flexibility
Maildoso historically required quarterly billing — locking you into 3-month commitments upfront. After sustained user complaints, they introduced monthly billing, but with caveats: on the monthly plan, domains are billed separately, adding hidden costs that inflate the real price even further. Winnr has always offered straightforward monthly billing with no lock-in and no hidden fees.
SURBL Blacklisting: Maildoso's Biggest Problem
Maildoso has a well-documented history of SURBL (Spam URI Realtime Blocklist) blacklisting — and it's part of a broader pattern of reliability problems that has plagued the platform. Multiple G2 reviews and Reddit threads describe recurring incidents where Maildoso-provided domains end up on SURBL, tanking deliverability for all users on those domains. When your domain is SURBL-listed, most major email providers will reject or spam-folder your messages entirely. Users have also reported broader service disruptions, inconsistent deliverability even outside of blacklisting events, and slow resolution times when issues arise.
SURBL blacklisting is a domain-level problem — once a domain lands on SURBL, every mailbox on that domain is effectively dead. What makes this worse with Maildoso is the replacement policy: when a burned .com domain is retired, users report being given replacement domains on low-trust TLDs like .xyz, .click, .top, and .store. These TLDs carry inherently lower reputation with mailbox providers, making deliverability even harder to achieve.
Winnr has not experienced SURBL blacklisting issues. All domains are registered on trusted TLDs, and Winnr's infrastructure is designed to isolate sending reputation at the account level rather than pooling risk across users.
Feature Comparison
| Feature | Winnr | Maildoso |
|---|---|---|
| DKIM / SPF / DMARC | Automatic on all accounts | Automatic on all accounts |
| REST API | Full API (create accounts, domains, DNS) | No API |
| Universal Mailbox (inbox) | Yes — unified inbox for all accounts | Basic — limited functionality |
| Dedicated IP | Available on Enterprise ($20/mo) | Not available |
| Bring Your Own Domain (BYOD) | Yes — use any domain you own | No — must register through Maildoso |
| Billing | Monthly, no lock-in | Monthly available (domains extra) or quarterly |
| Deliverability Guarantee | 90%+ with full refund | No published guarantee |
| Support | Email + live chat | Email support |
| Bulk Actions | Yes — bulk manage mailboxes & domains | Limited |
| Built-in Domain Purchasing | Yes — buy domains directly in the dashboard | Yes — but no BYOD option |
| One-Click Export | Yes — export all accounts instantly | No |
| Reliability Track Record | Clean — no documented outages or blacklisting | Spotty — recurring blacklisting & service disruptions |
| SURBL Blacklisting History | None documented | Recurring — documented on G2 & Reddit |
API Access: A Major Differentiator
Winnr offers a full REST API that lets you programmatically create mailboxes, register domains, configure DNS, and manage your entire infrastructure. This is critical for agencies and teams that need to onboard clients at scale or integrate email infrastructure into their existing workflows.
Maildoso does not offer an API. Everything must be done manually through their dashboard. For a solo sender managing a handful of accounts, this may be acceptable. For anyone scaling beyond that — agencies, SaaS platforms, or teams managing multiple client campaigns — the lack of API access is a serious limitation.
Bring Your Own Domain (BYOD)
Winnr supports BYOD — you can bring any domain you already own and set up mailboxes on it. This gives you full control over your domain portfolio, lets you use your preferred registrar, and means you're never locked into a platform's domain inventory.
Maildoso requires you to register domains through their platform. You cannot bring external domains. This creates vendor lock-in: if you leave Maildoso, you may lose access to your domains or face a complicated transfer process.
Deliverability Guarantee
Winnr offers a 90%+ inbox placement guarantee backed by a full refund if the guarantee isn't met. This is a concrete, measurable commitment that gives you confidence in the infrastructure you're paying for.
Maildoso does not publish a deliverability guarantee — and given their track record, that's a red flag. Users have consistently reported inconsistent deliverability, with some campaigns performing adequately while others crater without explanation. Combined with the documented SURBL blacklisting issues and service disruptions, there's no safety net if (or when) their infrastructure problems affect your campaigns. You're paying a premium with no assurance of results.
Pros & Cons at a Glance
Winnr Pros
- 40–55% cheaper per mailbox at every tier
- Full REST API for automation & integrations
- BYOD — bring any domain you own
- Built-in domain purchasing directly in the dashboard
- Bulk actions for managing mailboxes & domains at scale
- One-click export of all account credentials
- Universal mailbox with full functionality
- Dedicated IPs available on Enterprise
- 90%+ deliverability guarantee with refund
- Simple monthly billing, no lock-in
- Clean reliability track record — no blacklisting or service disruptions
Maildoso Cons
- ~55% more expensive per mailbox — significantly higher cost for fewer features
- No API — everything must be done manually
- No BYOD — domains must be registered through Maildoso, creating vendor lock-in
- No bulk actions — tedious to manage at scale
- No one-click export — difficult to migrate away
- Spotty reliability track record with recurring service disruptions
- Recurring SURBL blacklisting (documented on G2/Reddit)
- Burned .com domains replaced with low-trust TLDs (.xyz, .click, .top)
- Inconsistent deliverability — results vary unpredictably
- No published deliverability guarantee
- Quarterly billing historically required; monthly plan has hidden domain fees
Who Should Choose Maildoso?
Honestly, it's hard to make a strong case for Maildoso in 2026. The platform offers a decent basic setup for solo senders who don't need API access, BYOD, bulk actions, or one-click export — but you're paying significantly more for that limited feature set. If you're comfortable with the higher cost, the lack of a deliverability guarantee, and the risk of recurring reliability issues and blacklisting, Maildoso can technically get the job done. But for the same money (or less), you can get a more capable and more reliable platform elsewhere.
Who Should Choose Winnr?
Winnr is the better choice for anyone who wants reliable infrastructure without overpaying. Specifically:
- Cost efficiency: 40–55% savings per mailbox adds up fast at scale — why pay more for less?
- API access: Essential for agencies, developers, and anyone automating infrastructure.
- Domain control: BYOD means you own your domains and can move freely between providers. Plus, built-in domain purchasing makes it easy to expand.
- Reliability you can count on: Clean track record with no SURBL blacklisting, no service disruptions, and a backed 90%+ deliverability guarantee.
- Power features: Bulk actions, one-click export, full universal mailbox — features Maildoso simply doesn't offer.
- Dedicated IPs: Available for Enterprise users who want full sending reputation isolation.
The Verdict
Maildoso has been around, but longevity hasn't translated into reliability or value. The platform's spotty track record — recurring SURBL blacklisting, inconsistent deliverability, service disruptions, and slow issue resolution — is well-documented across user reviews. On top of that, Maildoso charges significantly more per mailbox while offering fewer features: no API, no BYOD, no bulk actions, no one-click export, and no deliverability guarantee.
Winnr is cheaper, more feature-rich, and more reliable. At 40–55% less per mailbox, with a full REST API, BYOD support, built-in domain purchasing, bulk management tools, one-click export, dedicated IPs, and a 90%+ deliverability guarantee — the value gap isn't close. If you're still on Maildoso, you're paying more for less and taking on unnecessary risk.
For a broader comparison with other cold email infrastructure providers, see our full competitor comparison guide.
Frequently Asked Questions
Is Maildoso cheaper than Winnr?
No — Maildoso is significantly more expensive. Winnr is 40–55% cheaper per mailbox. At 50 mailboxes, Winnr costs $69/mo ($1.38/mailbox) compared to Maildoso's ~$155/mo (~$3.10/mailbox). You're paying more than double per mailbox with Maildoso, and getting fewer features for the money.
Does Maildoso have SURBL blacklisting problems?
Yes — and it's part of a broader pattern of reliability issues. Maildoso has a well-documented history of recurring SURBL blacklisting, reported across G2 reviews and Reddit threads. When domains land on SURBL, all mailboxes on those domains suffer severe deliverability damage. Users have also reported general service disruptions and inconsistent deliverability outside of blacklisting events. Maildoso has been known to replace burned .com domains with low-trust TLDs like .xyz and .click, further hurting results.
Can I use my own domains with Maildoso?
No. Maildoso requires you to register domains through their platform — they do not support Bring Your Own Domain (BYOD). Winnr supports BYOD, letting you use any domain from any registrar.
Does Winnr have an API?
Yes. Winnr provides a full REST API that allows you to programmatically create mailboxes, register domains, manage DNS records, and automate your entire email infrastructure. Maildoso does not offer API access.
Which is better for agencies?
Winnr is significantly better for agencies. The REST API enables automated client onboarding and infrastructure management at scale. BYOD support lets you manage client domains without vendor lock-in. Bulk actions and one-click export make managing large account portfolios practical. Lower per-mailbox pricing improves margins. And the 90%+ deliverability guarantee provides a safety net you can pass through to your clients — something Maildoso simply can't offer given their inconsistent track record.