--- title: "MailDeck | Scalable Cold Email Infrastructure" description: "The world's most scalable inbox architecture for cold email teams sending 100k+ monthly. Zero configuration. Total deliverability control." canonical: "https://maildeck.co/" last-updated: "2026-08-22" --- > The world's most scalable inbox architecture for cold email teams sending 100k+ monthly. Zero configuration. Total deliverability control. 30% OFF YOUR FIRST ORDER MAILDECK [Go to Dashboard](https://app.maildeck.co)[Bible](https://maildeck.co/guideline) # Private Cold Email Infra. Built for scale. Trusted by the highest sender cold email teams sending millions monthly. Built by cold emailers for cold emailers with scaleability and deliverability as primary focus. Fully managed. 24/7 deliverability audit. 833.9K+ Inboxes Managed 7.5M+ Emails / Day 1631+ Global Clients [Order Inboxes](https://app.maildeck.co) Trustpilot 4.8 Google 4.9 Exclusive Access ## Stay Ahead of the Competition. To new inbox launches, restocks and special discounts, we also send 1 email tip every day except Sundays. * Disable AdBlock if the subscription form is not visible Scaling Room THE DEPLOYMENT CYCLE ## The All-in-One Solution for Reliable Performance. 01 ORDER STAGE 02 DELIVERY STAGE 03 SUCCESS STAGE 01 ORDER STAGE ### Place Your Order Choose your inbox package and place your order. Our process is quick and straightforward to get you started fast. Order Inboxes Add Domains Add Sequencer Information Add Domain Platform Information 1. Select Email Provider O OUTLOOKProfessional enterprise hosting. M GOOGLEStandard Workspace scaling. 2. Add Domains CSV acme-growth.com, acme-leads.io, acme-outreach.net + Add Domains DEMAND GENERATION ## From Blank Grids to Saturated Pipelines. Watch your empty operational window transform into a high-density revenue engine with surgical precision. Scaling Room INFRASTRUCTURE CORE 5G.V4 STABLE INBOXES 0 SCALING MAGNITUDE0% CAPACITY Scaling Room logo INBOXES 0 [QUICK START](https://app.maildeck.co) [PROCEED](https://app.maildeck.co) OPERATIONAL WINDOW ### — PROJECTION SYSTEM LIVE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 1 [QUICK START](https://app.maildeck.co) [PROCEED](https://app.maildeck.co) *Estimated. The results depend on several factors including offer quality and sending volume. Infrastructure Standard ## Why Industry Leaders Choose MailDeck? "Cold email infrastructure across Microsoft 365, Google Workspace, and SMTP. Fully configured, fully managed, ready in 48-72 hours." Microsoft 365, Google Workspace, and SMTP under one provider Official Microsoft and Google IPs, never shared pools Full "turnkey" setup in 48-72 hours Loaded into your sending program automatically Warm-up included, ready to send from day one Free domain replacement on burn 24/7 priority support [Order Inboxes](https://app.maildeck.co) The Proof Layer ## Trusted by High-Volume Teams. Discord Discord Community Join +950 Experts Mike Wentworth Director of Outbound | HR Tech Solutions 12k leads reached. 1,697 unique replies. 831 positive responses. that's a +5% reply rate and +45% of replies were interested. we've been running this for a quarter now and our domains are still healthy. Sabo and his team really set our infrastructure up like its their own. Mike Wentworth Success Metrics Tommy Vaughn Marketing Agency (EdTech Niche) Small team, needed big results. Under 10k emails out, +500 replies, more than 200 interested of MailDeck helped us punch way above our weight class without needing a huge SDR team. Tommy Vaughn Success Metrics David N. Fintech Agency Owner REACHED 1297 LEADS and 149 REPLIED and 31 SHOWED REAL INTEREST. We were skeptical about cold email after getting burned by a previous vendor who destroyed dozens of our domains, but Maildeck's 20.8% positive reply rate proved us wrong. Their warmup system actually works. David N. Success Metrics Mike Chen b2b saas growth partner we used to obsess over opens. with maildeck we mostly watch replies, bounces and how many calls land on the calendar. around 180–200k sends a month, 3-5% replies HUMAN!, nothing crazy. but it’s stable, and their infra guys ping us before things break, not after. Mike Chen Success Metrics Marcus L. Founder, AdGravity Ecom We blew up hundreds of domains last year sending pretty HTML newsletters as ‘cold outreach’. Maildeck made us strip everything back to 1–2 line, plain‑text notes and 3-5 cold emails per inbox per day. Felt underpowered at first, until we realized we were actually booking more discovery calls from half the volume. Marcus L. Success Metrics Michael Walter. Co‑Founder, SentinelSec Cyber Cyber clients are allergic to spammy tools, so we were cautious. Maildeck started us with slow warmup, rigid verification, and zero tracking or links. We hover around 6% reply rate on 10–12k sends/month, but the important part is we haven’t had a single tenant locked or reputation fire drill since switching. Michael Walter. Success Metrics Jake Rodriguez Founder @ Real Estate Agency We tested three sequences - 81k, 42k, and 62k emails. The middle campaign crushed it: 11% reply rate, +45% positive responses. Maildeck's team helped us dial in the messaging for each segment. No more spray and pray. Jake Rodriguez Success Metrics Jenna M. SignalStack Data Studio Data enrichment agency here. Honestly thought tools didn’t matter, only lists. Turns out infra + rules matter a lot when Outlook is watching everything. We send around 500k cold emails over multiple tenants got around 5% reply rates +40% positive replies, $300k/mo in the pipeline in first two months bounce under 1.5%. Jenna M. Success Metrics Alex G. Director, NovaChannel Outbound Collective We manage outbound for a mix of agencies, consultants and SaaS founders. Maildeck’s whole ‘TAM + angle first, then scale’ thing forced us to stop guessing. Now we stagger tests, track repl to positive to call for each angle, and only ramp what proves itself. We sit a bit above 850k sends/month, but it never feels reckless because each inbox is throttled and watched. Alex G. Success Metrics Chen Wei B2B Consulting - Healthcare IT Started small to test the waters (50k emails). Got 147 positive replies Gave us confidence to scale up to our big 200k campaign next, can’t wait to go even higher. Sabo's team really understands gradual scaling. Chen Wei Success Metrics ALEX KOWALSKI Head of Growth, FinTech Company 163,085 emails. 10,981 replies. 4,742 interested prospects. those are the numbers from our last 10 days. the reply rate sits at 6.73% which might not sound huge but when you're doing volume like this it's a FLOOD of conversations. bounce rate stayed at 1.31% the whole time. maildeck's infrastructure is legit. ALEX KOWALSKI Success Metrics Steven Grant Co-Founder, AI Automation Agency Two months, 246,263 emails sent, 2,479 replies (5.38% rate), 1,280 marked as interested (51.64% of replies were positive). Only 2569 bounces across the entire 60-day period. This is sustainable outbound - not the burn-and-churn approach we dealt with before. Steven Grant Success Metrics Mike Wentworth Director of Outbound | HR Tech Solutions 12k leads reached. 1,697 unique replies. 831 positive responses. that's a +5% reply rate and +45% of replies were interested. we've been running this for a quarter now and our domains are still healthy. Sabo and his team really set our infrastructure up like its their own. Mike Wentworth Success Metrics Tommy Vaughn Marketing Agency (EdTech Niche) Small team, needed big results. Under 10k emails out, +500 replies, more than 200 interested of MailDeck helped us punch way above our weight class without needing a huge SDR team. Tommy Vaughn Success Metrics David N. Fintech Agency Owner REACHED 1297 LEADS and 149 REPLIED and 31 SHOWED REAL INTEREST. We were skeptical about cold email after getting burned by a previous vendor who destroyed dozens of our domains, but Maildeck's 20.8% positive reply rate proved us wrong. Their warmup system actually works. David N. Success Metrics Mike Chen b2b saas growth partner we used to obsess over opens. with maildeck we mostly watch replies, bounces and how many calls land on the calendar. around 180–200k sends a month, 3-5% replies HUMAN!, nothing crazy. but it’s stable, and their infra guys ping us before things break, not after. Mike Chen Success Metrics Discord Discord Community Join +950 other cold email experts Maya AI assistant In-App AI Assistant ## Meet Maya. Your guide through the cold email stack. Ask Maya anything about the cold email stack — infrastructure, lists, personalization, replies. She explains how the system works. Chat with Maya Free [Install Extension](https://chromewebstore.google.com/detail/maya-%E2%80%94-cold-email-setup-a/ojbddegealjcfjmhagiifacpbcjoneic) Internal Schematic 0.94-B ## Deliverability Architecture. We don't hope for the primary inbox. We engineer the path to it using a four-layer verification stack. Infrastructure Authentication Warm-up Engine Inbox Rotation Enterprise Isolation Protocol Our proprietary system ensures that if one inbox is flagged, the entire fleet remains undetected. 99.8% Placement 0ms Latency Efficiency Audit ## You Are Drastically Undersending. Visibility is the Issue, Not Your Website or Offer. Not enough people are seeing your outreach. Imagine how many more meetings you would book with 20x more outreach for the same money. 01. Limited TAM? Scaling Markets This is easily fixed by scaling horizontally into adjacent markets or vertically. 02. Scaling Costs Too Much? 20x Cost Reduction You are being overcharged by Microsoft and resellers by upto 20x, that ends here. 03. Complex Setup Process? Automated Hardening Setting up DNS records, DKIM, SPF, and DMARC for each account is time-consuming and technical. We handle it all. Expenses Cost Comparison (1,000 Inboxes) Google / Outlook / Others 7,500$/mo MailDeck 550$/mo Read Case Study COMPETITIVE ANALYSIS ## Platform Benchmarking. A technical deep-dive into how MailDeck infrastructure stacks up against traditional methods. Deliverability Private SMTP Poor From Start Standard Resellers Burnt in 1-2 Weeks Microsoft Directly Highest MailDeck Highest User IP Private SMTP Varies Standard Resellers Asia Microsoft Directly Varies MailDeck US/EU only Pricing per Inbox Private SMTP $3-4/month Standard Resellers $1-2/month Microsoft Directly $7.5/month MailDeck $0.45/month Tool Integration Private SMTP Limited or manual Standard Resellers Limited Microsoft Directly Limited MailDeck Seamless tools Support Quality Private SMTP Minimal support Standard Resellers Limited avail. Microsoft Directly Standard hours MailDeck 24/7 support Email Setup Private SMTP Manual setup Standard Resellers Not included Microsoft Directly Not included MailDeck Included DNS Config Private SMTP Not configured Standard Resellers Configured Microsoft Directly Not configured MailDeck Complete DNS Poor From Start Burnt in 1-2 Weeks Highest Varies Asia Varies US/EU only $3-4/month $1-2/month $7.5/month $0.45/month Limited or manual Limited Seamless tools Minimal support Limited avail. Standard hours 24/7 support Manual setup Not included Included Not configured Configured Not configured Complete DNS | Features | Private SMTP | Standard Resellers | Microsoft Directly | MailDeck | |---|---|---|---|---| | Deliverability | | | | | | User IP | | | | | | Pricing per Inbox | | | | | | Tool Integration | | | | | | Support Quality | | | | | | Email Setup | | | | | | DNS Config | | | | | * Comparison based on Q4 2024 active performance data ## Choose Your Foundation. Transparent, high-volume pricing with zero hidden implementation fees. Microsoft Outlook Google Workspace SMTP Diversified StackNew Pre-Warmed Inboxes Both tiers use official Microsoft IP pools. Premium adds extra deliverability configuration for faster warmup (3-5 days) and higher volume (8-10 sends/inbox/day). Normal is the lowest-cost option (4-5 sends/inbox/day) for buying volume across more domains. Limited Offer: Extra 30% SaleSale 30% Volume CalculatorCalculator Normal License $45 $30/month per domain 100 Inboxes / Domain Azure 100 Inboxes / Domain 4-5 cold emails safely per inbox/day 500+ emails / day sending volume / domain Complete Technical Setup Free Domain Replacement Individual US Microsoft Tenants +15 Sending Tool Integration Intercom Chat Support Min. order: 2 tenants [Place Your Order](https://app.maildeck.co) Before You Purchase Don't leave your pipeline exposed. We recommend keeping 50% of your capacity as a warm reserve, always ready to absorb a full provider outage. Follow the golden backup ratio: 50% Outlook for high-trust bulk, 30% SMTP for cheap volume, and 20% Google for highest deliverability. ← Back to Plan Most Popular Premium License $55 $40/month per domain 100 Inboxes / Domain Azure 100 Inboxes / Domain 8-10 cold emails safely per inbox/day 500+ emails / day sending volume / domain Complete Technical Setup Free Domain Replacement Individual US Microsoft Tenants +15 Sending Tool Integration Intercom Chat Support Min. order: 2 tenants [Place Your Order](https://app.maildeck.co) Before You Purchase Don't leave your pipeline exposed. We recommend keeping 50% of your capacity as a warm reserve, always ready to absorb a full provider outage. Follow the golden backup ratio: 50% Outlook for high-trust bulk, 30% SMTP for cheap volume, and 20% Google for highest deliverability. ← Back to Plan Mixed License $50 $35/month per domain 50 Normal + 50 Premium Outlook licenses Azure 100 Inboxes / Domain 50 Normal + 50 Premium licenses per domain 500+ emails / day sending volume / domain Complete Technical Setup Free Domain Replacement Individual US Microsoft Tenants +15 Sending Tool Integration Intercom Chat Support Min. order: 2 tenants [Place Your Order](https://app.maildeck.co) Before You Purchase Don't leave your pipeline exposed. We recommend keeping 50% of your capacity as a warm reserve, always ready to absorb a full provider outage. Follow the golden backup ratio: 50% Outlook for high-trust bulk, 30% SMTP for cheap volume, and 20% Google for highest deliverability. ← Back to Plan Custom Plan - $?/month 100+ Inboxes / Domain Azure 100+ Inboxes / Domain Custom volume configuration Complete Technical Setup Free Domain Replacement Individual US Microsoft Tenants +15 Sending Tool Integration Dedicated Account Manager Slack 1:1 Support [Contact Us](https://wa.me/36308989894?text=Hi%2C%20I'm%20interested%20in%20a%20Custom%20Plan) Before You Purchase Don't leave your pipeline exposed. We recommend keeping 50% of your capacity as a warm reserve, always ready to absorb a full provider outage. Follow the golden backup ratio: 50% Outlook for high-trust bulk, 30% SMTP for cheap volume, and 20% Google for highest deliverability. ← Back to Plan Scaling Room OUR ECOSYSTEM ## Scaling Room Try our other products for high-performance outreach EmailShield [EMAILSHIELD](https://emailshield.co) [Email Intelligence](https://emailshield.co) Scaling Room [Scaling Room](https://scalingroom.com/) [ECOSYSTEM MARKETPLACE](https://scalingroom.com/) LeadSonar [LEADSONAR](https://leadsonar.io) [find & enrich leads](https://leadsonar.io) RESEARCH & INSIGHTS ## Technical Field Reports. Deep dives into deliverability architecture, reputation management, and scaling outbound operations. Cold Email Infrastructure Cost: 2026 Pricing Comparison Across 11 Providers [Guide](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) [Mar 25, 2026](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) [11 min](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) ### [Cold Email Infrastructure Cost: 2026 Pricing Comparison Across 11 Providers](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) [We analyzed pricing of 11 cold email infrastructure providers at 100, 500, 1,000 and 5,000 inbox scale. Full cost breakdown with per-inbox rates.](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) [Read Article](https://maildeck.co/blog/cold-email-infrastructure-cost-2026) Cold Email Domain Rotation: When and How to Rotate Sending Domains [Guide](https://maildeck.co/alternative/cold-email-domain-rotation) [Apr 06, 2026](https://maildeck.co/alternative/cold-email-domain-rotation) [12 min](https://maildeck.co/alternative/cold-email-domain-rotation) ### [Cold Email Domain Rotation: When and How to Rotate Sending Domains](https://maildeck.co/alternative/cold-email-domain-rotation) [10-20% of cold email domains burn monthly at scale. Complete domain rotation strategy with specific thresholds, timelines, and recovery protocols based on data from 1,200+ domains.](https://maildeck.co/alternative/cold-email-domain-rotation) [Read Article](https://maildeck.co/alternative/cold-email-domain-rotation) Cold Email Deliverability Checklist: 15-Point Audit Template [Guide](https://maildeck.co/alternative/cold-email-deliverability-checklist) [Apr 20, 2026](https://maildeck.co/alternative/cold-email-deliverability-checklist) [10 min](https://maildeck.co/alternative/cold-email-deliverability-checklist) ### [Cold Email Deliverability Checklist: 15-Point Audit Template](https://maildeck.co/alternative/cold-email-deliverability-checklist) [Copy-paste deliverability checklist based on 50M+ emails/month across 3,000+ domains. 15 infrastructure, DNS, and campaign checks that maintain 98% inbox placement.](https://maildeck.co/alternative/cold-email-deliverability-checklist) [Read Article](https://maildeck.co/alternative/cold-email-deliverability-checklist) Cold Email Warm Up: What Actually Works in 2026 [Guide](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) [Apr 16, 2026](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) [11 min](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) ### [Cold Email Warm Up: What Actually Works in 2026](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) [Day-by-day warm-up schedule backed by data from 833K+ inboxes. What warm-up metrics matter, common mistakes that kill deliverability, and how to fix warm-up that stopped working.](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) [Read Article](https://maildeck.co/alternative/cold-email-warm-up-what-actually-works-2026) Cold Email ROI Calculator: Revenue and Cost Per Lead [Guide](https://maildeck.co/alternative/cold-email-roi-calculator) [Apr 28, 2026](https://maildeck.co/alternative/cold-email-roi-calculator) [9 min](https://maildeck.co/alternative/cold-email-roi-calculator) ### [Cold Email ROI Calculator: Revenue and Cost Per Lead](https://maildeck.co/alternative/cold-email-roi-calculator) [Interactive cold email ROI calculator with data from 833K+ managed inboxes. Calculate cost per lead, cost per meeting, monthly revenue, and compare against SDR costs.](https://maildeck.co/alternative/cold-email-roi-calculator) [Read Article](https://maildeck.co/alternative/cold-email-roi-calculator) Cold Email Infrastructure Diversification: Why One Provider Isn't Enough [Guide](https://maildeck.co/alternative/cold-email-infrastructure-diversification) [Apr 22, 2026](https://maildeck.co/alternative/cold-email-infrastructure-diversification) [10 min](https://maildeck.co/alternative/cold-email-infrastructure-diversification) ### [Cold Email Infrastructure Diversification: Why One Provider Isn't Enough](https://maildeck.co/alternative/cold-email-infrastructure-diversification) [Data from 833K+ inboxes shows diversified infrastructure delivers 15-50% better inbox placement than single-provider setups. The 50/30/20 ratio explained.](https://maildeck.co/alternative/cold-email-infrastructure-diversification) [Read Article](https://maildeck.co/alternative/cold-email-infrastructure-diversification) How Many Inboxes Do You Actually Need? Data from 500+ Cold Email Campaigns [Guide](https://maildeck.co/blog/how-many-inboxes-cold-email) [Mar 26, 2026](https://maildeck.co/blog/how-many-inboxes-cold-email) [13 min](https://maildeck.co/blog/how-many-inboxes-cold-email) ### [How Many Inboxes Do You Actually Need? Data from 500+ Cold Email Campaigns](https://maildeck.co/blog/how-many-inboxes-cold-email) [5 emails per Outlook inbox per day. That's the rule for Microsoft 365. We break down exactly how many inboxes you need for 10K, 50K, 100K, and 1M+ emails/month.](https://maildeck.co/blog/how-many-inboxes-cold-email) [Read Article](https://maildeck.co/blog/how-many-inboxes-cold-email) [Explore Intelligence Center](https://maildeck.co/blog) Knowledge Base ## Got Questions? Everything you need to know about our infrastructure. What is MailDeck? MailDeck is a cold email infrastructure provider managing 833.9K+ inboxes for 1,631+ clients across three platforms: Microsoft 365 Outlook, Google Workspace, and Private SMTP. Most competitors specialize in one infrastructure type. MailDeck covers all three so teams can match their infrastructure to their target audience. Based on Q1 2026 platform data. What is cold email infrastructure? Cold email infrastructure is the technical setup required to send high-volume outreach emails reliably. It includes dedicated sending domains, mailboxes, DNS authentication (SPF, DKIM, DMARC), IP warmup, and ongoing deliverability monitoring. The choice of infrastructure (Microsoft 365 Outlook, Google Workspace, or SMTP) determines roughly 60% of deliverability. Domain health, copy quality, and list quality determine the rest. What infrastructure types does MailDeck support? MailDeck supports three infrastructure types under one provider: Microsoft 365 Outlook (Azure tenants with dedicated US IPs, 100 inboxes per tenant), Google Workspace (real Starter accounts on Google's official IP pools, 5 inboxes per domain), and Private SMTP (dedicated IP per client, 5 inboxes per domain). All three are equally supported. How much does MailDeck cost? Microsoft 365 Outlook tenants start at $30 per tenant for the Normal Licence ($0.30 per inbox, 100 inboxes per tenant). Premium Licence is $40 per tenant ($0.40 per inbox). Mixed Licence (50 Normal + 50 Premium per tenant) is $35 per tenant. Pre-Warmed Outlook inboxes are $40 per tenant. Google Workspace plans start at $39 per month for 10 inboxes ($3.90 per inbox), with Growth at $99 per month for 30 inboxes and Enterprise at $299 per month for 100 inboxes. Private SMTP is $0.50 per inbox with a 100-inbox minimum ($50/month). Diversified Stack plans combining all three start at $99 per month. Which MailDeck product has the best deliverability? Google Workspace inboxes deliver the highest inbox placement because they use Google's official IP pools, which carry the highest trust score across receiving servers worldwide. Microsoft 365 Outlook is second, also using bulletproof official Microsoft IP pools. Private SMTP is fourth because reputation is built from scratch per client. Across the entire MailDeck platform, average inbox placement holds at 98%. How quickly are MailDeck inboxes provisioned? Provisioning times differ by product. Google Workspace inboxes are provisioned instantly. Private SMTP inboxes are delivered within 24 hours. Microsoft 365 Outlook inboxes take 2-3 business days because Azure tenant provisioning involves Microsoft-side setup. All three products include full SPF, DKIM, and DMARC configuration plus end-to-end DNS verification before the first email is sent. How many cold emails can I send per inbox per day? Microsoft 365 Outlook Normal Licence supports 4-5 cold emails per inbox per day. Microsoft 365 Outlook Premium Licence supports 8-10. Google Workspace supports 18-22. Private SMTP supports 11-14. These limits are based on Q1 2026 MailDeck platform data and are tuned to maintain inbox placement above 95% across receiving servers. How many inboxes do I need for cold email? Inbox count depends on monthly send volume and infrastructure mix. For 100K emails per month using a Diversified Stack at the recommended 50/30/20 ratio, roughly 16 domains are needed: 3 Microsoft 365 Outlook tenants (300 inboxes), 6 Private SMTP domains (30 inboxes), and 7 Google Workspace domains (33 inboxes). For higher volumes the math scales linearly. A 1M sends per month operation typically requires 150-200 active domains plus a 20-25% warm reserve. How long does cold email warm-up take? Microsoft 365 Outlook Premium Licence requires 3-5 days minimum, ideally 10-14 days. Microsoft 365 Outlook Normal Licence requires 5-7 days minimum, ideally 10-14 days. Google Workspace requires 15 days minimum, ideally 20-25 days. Private SMTP requires 3-4 weeks minimum and 6+ weeks for high-volume use. MailDeck Pre-Warmed Outlook inboxes at $40 per tenant skip warmup entirely and are ready for cold sending immediately. Does MailDeck use shared IPs? No. MailDeck never uses shared IPs. Microsoft 365 Outlook inboxes use official Microsoft IP pools, which are whitelisted across virtually every receiving server. Google Workspace inboxes use official Google IP pools, which carry the highest trust score on the internet. Private SMTP uses dedicated IPs per client where reputation is built from scratch and is never shared with other senders. Does MailDeck handle DNS authentication? Yes. MailDeck automates SPF, DKIM, and DMARC setup for every domain. DNS propagation and end-to-end authentication are verified before the first email is sent. A MailDeck DNS audit of 1,000+ domains found that 67% had at least one critical authentication error. The most common errors were multiple SPF records on one domain (23%), missing DMARC record (19%), and SPF ending with +all (14%). Does MailDeck work with Instantly, Smartlead, and other sequencers? Yes. All MailDeck inboxes connect via SMTP to every major sequencer including Instantly, Smartlead, Saleshandy, Apollo, Lemlist, Woodpecker, Reply.io, Snov.io, QuickMail, GMass, Klenty, Mailshake, and any SMTP-compatible outreach tool. The sequencer is a scheduler and does not affect deliverability. Inbox type, domain health, copy quality, and list quality determine deliverability. Do I need to bring my own domains? Yes. Clients bring their own domains. MailDeck handles full DNS configuration, SPF, DKIM, and DMARC setup, and propagation verification on the domains the client provides during onboarding. How does MailDeck compare to Maildoso, Infraforge, and Mailforge? MailDeck Microsoft 365 Outlook inboxes start at $0.30 per inbox on official Microsoft IP pools. Maildoso uses shared IP pools at approximately $2.50 per inbox, carrying shared IP risk where one bad sender hurts all clients. Infraforge is Microsoft-only at approximately $4.00 per inbox without official Microsoft IPs. Mailforge uses shared IP SMTP at approximately $3.00 per inbox with shared IP risk. MailDeck is the only provider in the niche offering Microsoft 365, Google Workspace, and SMTP under one platform with zero shared IP exposure. What happens if a domain gets burned? MailDeck includes free domain replacement when a domain burns under normal sending conditions. At enterprise scale (100K+ emails per month) approximately 10-20% of cold email domains burn monthly with domain lifespan ranging 45 days to 2 months under active load. MailDeck recommends maintaining a 20-25% warm reserve so replacement happens within 1-3 days without breaking campaign cadence. Without reserves, replacement takes 7-10 days. What cold email copy rules should I follow? Copy rules differ significantly by provider. Google Workspace inboxes are the most permissive: links, open tracking, and ESP matching (Google-to-Google) are safe to use, and images in signatures are acceptable. Microsoft 365 Outlook (both Normal and Premium) requires strict rules: no links in body copy because the Safe Links scanner triggers, no open tracking because Outlook checks messages before delivery and tracking pixels spike spam detection, no ESP matching, no dollar signs or financial language, maximum 50 words per email, and spintax on every 2-3 words. Private SMTP should never be used as the primary sending protocol and is best capped at 30% of total send volume to absorb spikes and protect premium inboxes. These rules are derived from data on 270M+ cold emails sent through the MailDeck platform. Who is MailDeck for? MailDeck serves the full range of cold email senders. 1,631+ clients across Q1 2026 platform data include solopreneurs running their own outbound at 30K-50K emails per month, small teams scaling from 50K to 100K, growing leadgen and outbound agencies managing 100K-300K emails per month across multiple clients, B2B sales teams targeting enterprise accounts, SaaS companies selling into mid-market and enterprise, and enterprise operations sending 1M+ per month. Platform sends 7.5M+ emails per day and has delivered 270M+ cold emails lifetime. What is the difference between MailDeck's Outlook Normal and Premium inboxes? Both run on the same official Microsoft Azure IP pools. Premium inboxes get additional deliverability configuration, so they warm up in 3-5 days and safely send 8-10 cold emails per inbox per day, while Normal inboxes warm up in 5-7 days and send 4-5 per day. On identical lists, Premium places 15-20% below Google Workspace versus 20-25% for Normal. Premium costs $0.40 per inbox, Normal $0.30. Choose Premium for higher trust and volume; choose Normal for the lowest cost per inbox. Based on Q1 2026 MailDeck platform data. How do I cancel? Cancel anytime through account settings. No long-term contracts and no cancellation fees. Still have more specific questions? Contact Support Ready to scale your outreach? [Go to Dashboard](https://app.maildeck.co)