# Mailionaire

> Microsoft 365 inboxes for cold email, built in Switzerland. Mailionaire provisions real, isolated Microsoft 365 mailboxes for cold email, sets up SPF, DKIM and DMARC, and keeps them healthy. Built and run in Switzerland, with optional EU/Swiss data residency. One flat price per active domain — no per-mailbox metering, no year-two price shock.

## What it is
Mailionaire is managed email infrastructure for cold email. It provisions real, isolated Microsoft 365 mailboxes (one tenant per sending domain), configures DNS (SPF, DKIM, DMARC), and monitors and replaces worn mailboxes and domains as they wear out. It is built and run in Switzerland.

## Key facts
- One sending domain = one isolated Microsoft 365 tenant = up to 100 mailboxes.
- Pricing: $50 per active domain per month. No base fee, no minimum, no per-mailbox metering.
- The price you see is the price that renews; there is no year-two price increase.
- Billing: one consolidated monthly invoice; add or remove domains with proration.
- Risk reversal: 14-day money-back guarantee instead of a free trial.
- European setup: built and run in Switzerland. With the optional EU/Swiss residency add-on (~+20%), mailboxes use EU/CH IP space and mailbox content sits at rest in the EU/Switzerland under the Microsoft EU Data Boundary. No other Microsoft 365 cold-email provider offers licensed M365 on EU/CH IPs. Residency is optional because US IP space usually delivers better for US recipients.
- Important caveat: European data residency does NOT make cold email legal. Consent law (e.g. Germany UWG §7(2), which requires opt-in even for B2B) still applies regardless of hosting location. The sender is always responsible for lawful sending.
- Operated by Mailionaire, Switzerland. Contact: support@mailionaire.ch.

## Core pages
- [Home](https://mailionaire.ch/): overview and value proposition.
- [How it works](https://mailionaire.ch/how-it-works): the provisioning flow, step by step.
- [European email infrastructure](https://mailionaire.ch/european-email-infrastructure): what EU/Swiss residency does and does not mean.
- [Pricing](https://mailionaire.ch/pricing): $50 per active domain, what is included.
- [About](https://mailionaire.ch/about): who operates Mailionaire.

## Guides (blog)
- [What Is Cold Email Infrastructure? A Plain-Language Guide](https://mailionaire.ch/blog/what-is-cold-email-infrastructure): Cold email infrastructure explained: domains, mailboxes, Microsoft 365 vs Google, SPF/DKIM/DMARC, warmup, deliverability, and why senders separate it.
- [What Is Mailbox Provisioning? A Plain Definition for Cold Email](https://mailionaire.ch/blog/what-is-mailbox-provisioning): Mailbox provisioning means preparing domains, tenants, mailboxes, and DNS so they can send email. Here is what it involves at scale and how to do it.
- [Best Cold Email Infrastructure Providers (2026 Comparison)](https://mailionaire.ch/blog/best-cold-email-infrastructure-providers-2026): An honest 2026 comparison of cold email infrastructure providers by email model, tenant isolation, EU residency, and pricing. Verify current prices before you buy.
- [Google and Yahoo Sender Requirements (for Cold Email)](https://mailionaire.ch/blog/google-yahoo-sender-requirements): The Google and Yahoo sender requirements explained: SPF, DKIM, DMARC, one-click unsubscribe, and keeping spam complaints low — what they mean for cold email.
- [Why Cold-Email Domains Burn Out — and How to Stay Ahead](https://mailionaire.ch/blog/why-cold-email-domains-burn-out): Why cold-email domains burn out: how spam complaints, low engagement, blacklisting, and DNS errors decay sender reputation — and how rotation keeps you ahead.
- [Cold Email and GDPR: A Practical Guide for Senders](https://mailionaire.ch/blog/cold-email-gdpr-guide): A practical cold email GDPR guide: lawful basis, legitimate interest, data-subject rights, and why processing rules differ from the act of sending.
- [Is Cold Email Legal? GDPR, ePrivacy, UWG and CAN-SPAM](https://mailionaire.ch/blog/is-cold-email-legal): Is cold email legal? It depends on the recipient's jurisdiction. A neutral overview of GDPR, ePrivacy, Germany's UWG, and CAN-SPAM rules.
- [Per-Mailbox vs Per-Domain Pricing for Cold Email](https://mailionaire.ch/blog/per-mailbox-vs-per-domain-pricing): Per mailbox vs per domain pricing for cold email: how each model scales with growth, which one forecasts cleanly, and why per-mailbox climbs fastest.
- [Microsoft 365 vs. Google Workspace vs. SMTP for Cold Email](https://mailionaire.ch/blog/microsoft-365-vs-google-workspace-smtp-cold-email): A fair, factual comparison of Microsoft 365, Google Workspace, and raw SMTP for cold email: setup, isolation, reputation model, cost, and real-world fit.
- [How Much Does Cold Email Infrastructure Cost? (2026)](https://mailionaire.ch/blog/cold-email-infrastructure-cost): Cold email infrastructure cost in 2026: per-mailbox vs per-domain pricing, the hidden labour cost, and how to compare models that scale differently.
- [EU Data Residency for Cold Email: What It Means (and What It Doesn't)](https://mailionaire.ch/blog/eu-data-residency-cold-email): EU data residency for cold email explains where mailbox data is stored and which IPs send. It does not make sending legal — GDPR and consent law still apply.
- [Domain Rotation for Cold Email: How and When](https://mailionaire.ch/blog/domain-rotation-cold-email): Domain rotation for cold email means staggering domain lifecycles, retiring worn domains, and keeping warmed replacements ready so sending capacity never collapses.
- [Manual vs. Managed Cold Email Infrastructure](https://mailionaire.ch/blog/manual-vs-managed-cold-email-infrastructure): Manual vs managed cold email infrastructure compared: who carries the operational load, where errors hide, and which model fits your team and volume.
- [How Many Mailboxes Per Domain? A Practical Guide for Cold Email](https://mailionaire.ch/blog/how-many-mailboxes-per-domain): How many mailboxes per domain for cold email? The common 50-100 pattern, low daily sends, warmup ramp, and why spreading volume protects sender reputation.
- [How to Scale Cold Email Without Burning Domains](https://mailionaire.ch/blog/how-to-scale-cold-email-sending): How to scale cold email: add domains and mailboxes, keep per-mailbox volume low, rotate sending, and monitor reputation so growth doesn't burn domains.
- [Cold Email Infrastructure for Agencies: How to Scale](https://mailionaire.ch/blog/cold-email-infrastructure-for-agencies): Cold email infrastructure for agencies: per-client isolation, many domains, predictable per-domain cost, and how to cut the operational load of managing it all.
- [The Year-Two Price Shock in Cold-Email Infrastructure](https://mailionaire.ch/blog/cold-email-infrastructure-year-two-price-shock): Why cold-email infrastructure pricing jumps at renewal: per-mailbox metering, low intro rates, tier changes, and why flat per-domain pricing forecasts better.
- [How Many Domains Do You Need for Cold Email?](https://mailionaire.ch/blog/how-many-domains-for-cold-email): How many domains for cold email? Work it out from your daily target with a simple formula, then add spare domains for rotation as they wear out.
- [The Cold Email Infrastructure Setup Checklist (2026)](https://mailionaire.ch/blog/cold-email-setup-checklist): A step-by-step cold email setup checklist for 2026: domains, isolated tenants, SPF/DKIM/DMARC, warmup, monitoring, and rotation — in the order that works.
- [Is Raw SMTP Good for Cold Email?](https://mailionaire.ch/blog/is-raw-smtp-good-for-cold-email): Raw SMTP relays for cold email: how they differ from real inboxes, the shared-IP problem, the missing reply path, and the few cases where SMTP actually fits.
- [What Is an MX Record? Email DNS Explained](https://mailionaire.ch/blog/what-is-an-mx-record): An MX record is the DNS entry that tells the internet which server receives email for your domain. Learn how MX priority works and how it relates to sending.
- [DNS Records for Email: MX, SPF, DKIM, DMARC Explained](https://mailionaire.ch/blog/dns-records-for-email): The DNS records every email sender needs — MX, SPF, DKIM, DMARC, and A/CNAME — what each one does and why it matters, in plain language for cold email.
- [Microsoft 365 vs. Azure for Cold Email: What's the Difference?](https://mailionaire.ch/blog/microsoft-365-vs-azure-cold-email): Microsoft 365 vs Azure for cold email explained: mailboxes vs platform, tenant isolation, what actually sends your outreach, and why the comparison is often a category error.
- [Microsoft Is Going OAuth-Only: What It Means for Cold Email](https://mailionaire.ch/blog/microsoft-oauth-only-2027-cold-email): Microsoft has been retiring basic authentication for SMTP and is moving Exchange Online toward OAuth-only. Here's what the shift means for cold email.
- [What Is a Cold Email Sequencer?](https://mailionaire.ch/blog/cold-email-sequencer-explained): A cold email sequencer schedules, sends, and tracks outbound campaigns from your mailboxes. Here is what it does and where infrastructure ends.
- [How to Choose Domains for Cold Email (TLDs and Variants)](https://mailionaire.ch/blog/how-to-choose-cold-email-domains): How to buy cold email domains: pick brand variants, favour established TLDs over cheap spam-prone ones, and keep sending domains separate from your main site.
- [Cold Email Domain Setup: Step-by-Step (2026)](https://mailionaire.ch/blog/cold-email-domain-setup): A step-by-step cold email domain setup guide for 2026: registrar, DNS, Microsoft 365 tenant, mailboxes, SPF/DKIM/DMARC, warmup, and connecting a sequencer.
- [Secondary Domains for Cold Email: Why Not Your Main Domain](https://mailionaire.ch/blog/secondary-domains-cold-email): Secondary domains for cold email keep outbound off your primary brand domain, containing reputation damage. Here's why operators use separate sending domains.
- [Shared vs Dedicated IPs for Cold Email Explained](https://mailionaire.ch/blog/shared-vs-dedicated-ip-cold-email): Shared vs dedicated IP for cold email: how each affects reputation, the warmup tradeoff of dedicated IPs, and why isolated Microsoft 365 tenants change the question.
- [What Is a Microsoft 365 Tenant? (Cold Email Context)](https://mailionaire.ch/blog/microsoft-365-tenant-explained): A Microsoft 365 tenant is an isolated cloud organization. Here is what that means for cold email, why isolation beats shared pools, and the one-tenant-per-domain pattern.
- [SPF, DKIM and DMARC: A Setup Checklist for Cold Email](https://mailionaire.ch/blog/spf-dkim-dmarc-setup-checklist): A step-by-step SPF, DKIM and DMARC setup checklist for cold email — publish all three, test a real send, and avoid the common authentication mistakes.
- [DMARC for Cold Email: Policies Explained](https://mailionaire.ch/blog/dmarc-cold-email): DMARC for cold email explained: how p=none, quarantine, and reject work, what alignment means, and how aggregate reporting shows you who sends as your domain.
- [DKIM for Cold Email: Signatures, Selectors, and Keys](https://mailionaire.ch/blog/dkim-cold-email): How DKIM works for cold email: how the signature is built, what selectors do, why 2048-bit keys matter, and when to rotate. A practical setup guide.
- [SPF Records for Cold Email: A Practical Guide](https://mailionaire.ch/blog/spf-record-cold-email): What an SPF record is, the 10 DNS-lookup limit, -all vs ~all, and why you keep one SPF record per domain — a practical guide for cold email senders.
- [How to Test Your Cold Email Deliverability](https://mailionaire.ch/blog/how-to-test-cold-email-deliverability): How to test email deliverability with seed tests, auth checks, blocklist lookups, and postmaster tools — what each method actually measures and what it misses.
- [Why Engagement Drives Cold Email Deliverability](https://mailionaire.ch/blog/email-engagement-deliverability): Engagement — opens, replies, and mail that gets kept — tells mailbox providers your mail is wanted. Learn how engagement signals shape cold email deliverability
- [Spam Traps: What They Are and How to Avoid Them](https://mailionaire.ch/blog/spam-traps-cold-email): What spam traps are, how pristine and recycled traps differ, and how scraped lists, stale data, and poor list hygiene get you hit — plus how to avoid them.
- [Email Blacklists Explained: How to Avoid and Recover](https://mailionaire.ch/blog/email-blacklists-cold-email): What an email blacklist is, what gets a cold-email domain or IP listed, how to check whether you are on one, and why delisting and recovery are slow.
- [Soft vs Hard Bounces: Managing Bounce Rate in Cold Email](https://mailionaire.ch/blog/email-bounce-rate-cold-email): What email bounce rate means in cold email, the difference between soft and hard bounces, and how to keep bounces low to protect sender reputation and deliverability.
- [What Is Domain Reputation and How to Build It](https://mailionaire.ch/blog/domain-reputation-cold-email): Domain reputation is the trust score mailbox providers attach to your sending domain. Learn what drives it — complaints, engagement, authentication — and how to build it.
- [How Many Cold Emails Can You Send Per Day Per Inbox?](https://mailionaire.ch/blog/how-many-cold-emails-per-day): How many cold emails per day per inbox? The honest number is low tens once warmed, ramped from near zero. Scale with more mailboxes, not a hotter inbox.
- [Cold Email Deliverability: The Complete Guide](https://mailionaire.ch/blog/cold-email-deliverability-guide): A complete guide to cold email deliverability: authentication, isolation, warmup, volume, complaints, engagement, and how delivery differs from inbox placement.
- [Why Are My Cold Emails Going to Spam? Causes and Fixes](https://mailionaire.ch/blog/why-cold-emails-go-to-spam): Why cold emails go to spam: a diagnostic checklist covering authentication, sender reputation, volume, content, and targeting — with the fix for each cause.
- [How Long Does Email Warmup Take?](https://mailionaire.ch/blog/how-long-does-email-warmup-take): How long does email warmup take? Plan for a multi-week ramp of roughly two to six weeks per mailbox. The exact timeline depends on volume and reputation.
- [What Is Email Warmup and How Does It Work?](https://mailionaire.ch/blog/what-is-email-warmup): Email warmup explained: what it is, how the gradual send ramp and engagement signals work, how long it takes, and why its real value is debated.

## Legal
- [Privacy](https://mailionaire.ch/privacy)
- [Terms](https://mailionaire.ch/terms)
- [Legal notice](https://mailionaire.ch/legal)