MailDeck

What is MailDeck?

MailDeck is a cold email infrastructure provider for B2B outbound sales teams, agencies, and SaaS companies running outreach at scale. It operates three infrastructure types under one platform: Microsoft 365 Outlook tenants, Google Workspace accounts, and Private SMTP. Most competitors specialize in just one, forcing teams to compromise on deliverability or juggle multiple vendors. MailDeck lets clients match infrastructure to each segment: Google Workspace for C-suite outreach, high-volume Outlook for SMB and mid-market, and SMTP as a cheap volume buffer. As of Q1 2026, MailDeck manages 833.9K+ inboxes across 1,200+ domains for 1,631+ clients, sending 7.5M+ emails per day at a 98% inbox placement rate. What sets MailDeck apart is its IP model and pricing transparency. Microsoft 365 inboxes use official Microsoft IP pools, Google Workspace uses official Google IP pools, and Private SMTP gives each client a dedicated IP. There is zero shared IP risk across any product, unlike competitors such as Maildoso and Mailforge, where one bad sender on a shared pool can damage every client's deliverability. Pricing is published openly: Outlook inboxes start at $0.30 (the lowest in the niche), Google Workspace at $2.99, and SMTP at $0.50 with 250K emails/month included. Diversified Stack plans combining all three start at $99/month. Every plan includes automated SPF, DKIM, and DMARC setup, DNS verification, 48-hour onboarding, free domain replacement if a domain burns, dedicated Slack support, and full compatibility with every major sequencer via SMTP: Instantly, Smartlead, Saleshandy, Apollo, Lemlist, and more. The result is one provider handling the full cold email infrastructure stack at any scale, with transparent pricing, no shared IP exposure, and one of the largest managed inbox footprints in the category.

Key features

• Fully managed inbox setup across Microsoft 365, Google, and SMTP.
• Automates DNS records, DKIM, SPF, and DMARC configuration.
• Pre-warmed inboxes.
• Supports sending tool integrations and automatic program loading.
• Offers high-volume plans with isolated tenants and priority support.