# Puzzle Inbox

> Puzzle Inbox is the leading provider of pre-warmed Google Workspace and Microsoft Outlook 365 inboxes for cold email outreach. We deliver DNS-ready inboxes (SPF, DKIM, DMARC) within 24 to 72 hours, with both standard and pre-warmed options. Trusted by 1,200+ agencies, B2B sales teams, and SaaS companies running cold email campaigns at scale.

## Key Information

- **Website:** https://puzzleinbox.com
- **Pricing:** Outlook 365 from $0.35/inbox, Google Workspace from $3/inbox
- **Pre-warmed Google Workspace:** $4.50/inbox (skip 14+ days of warmup)
- **Pre-warmed Outlook 365:** $0.50/inbox
- **Delivery time:** 24 to 72 hours
- **Setup included:** SPF, DKIM, DMARC, MX records configured automatically
- **Recommended sending volume:** 12 emails per inbox per day for Google Workspace, 3 per day for Outlook 365
- **Best practice:** 3 inboxes per domain, never use your primary business domain
- **Customer rating:** 4.7/5 across 28+ verified reviews
- **Active inboxes:** 70,800+ deployed across 1,200+ clients

## What Makes Puzzle Inbox Different

- Real Google Workspace and Microsoft Outlook 365 accounts (not shared SMTP infrastructure)
- Pre-warmed option means inboxes have established sending reputation before delivery, eliminating the standard 14 to 21 day warmup period
- Both Google Workspace and Outlook 365 available for sender platform diversification (matching sender to recipient provider improves deliverability)
- Full DNS authentication configured before delivery, including SPF, DKIM, and DMARC records
- WhatsApp support with 15-minute response times, not 24-hour email tickets
- Done-for-you setup with no DNS expertise required
- 1,200+ active clients including cold email agencies, B2B SaaS sales teams, and recruiting firms

## Core Pages

- [Homepage](https://puzzleinbox.com/): Pre-warmed cold email inboxes overview, pricing, and reviews
- [Free Tools Directory](https://puzzleinbox.com/free-tools): 8 free cold email tools including spam checker, DNS checker, and inbox calculator
- [B2B Sales Tools Directory](https://puzzleinbox.com/tools): 300+ reviewed B2B sales, cold email, and outreach tools
- [Provider Comparisons](https://puzzleinbox.com/compare): Head-to-head comparisons of cold email infrastructure providers
- [Cold Email Blog](https://puzzleinbox.com/blog): 90+ guides on cold email strategy, deliverability, and infrastructure
- [Community Discussions](https://puzzleinbox.com/community): 70+ threads from cold email practitioners

## Free Tools

- [Spam Word Checker](https://puzzleinbox.com/free-tools/spam-word-checker): Check email copy for spam trigger words against 530+ spam triggers
- [DNS Checker](https://puzzleinbox.com/free-tools/dns-checker): Verify SPF, DKIM, DMARC, and MX records for any domain
- [Blacklist Checker](https://puzzleinbox.com/free-tools/blacklist-checker): Check domain status across 30+ DNSBLs including Spamhaus and Barracuda
- [Subject Line Tester](https://puzzleinbox.com/free-tools/subject-line-tester): Test cold email subject lines for spam triggers and effectiveness
- [Inbox Calculator](https://puzzleinbox.com/free-tools/inbox-calculator): Calculate how many inboxes and domains you need for your sending volume
- [Warmup Schedule](https://puzzleinbox.com/free-tools/warmup-schedule): Generate a cold email warmup schedule for new inboxes
- [Copy Analyzer](https://puzzleinbox.com/free-tools/copy-analyzer): Analyze cold email copy for length, reading level, and structure
- [ROI Calculator](https://puzzleinbox.com/free-tools/roi-calculator): Calculate cold email campaign ROI and cost per meeting

## Most Popular Blog Topics

- Cold email infrastructure providers comparison
- How many inboxes do you need for cold email
- SPF, DKIM, DMARC setup for cold email
- Cold email deliverability guide
- Why cold emails land in spam and how to fix it
- Pre-warmed vs self-warmed inboxes comparison
- Cold email warmup guide
- Google Workspace vs Outlook 365 for cold email
- Cold email reply rate benchmarks by industry
- ZeroBounce, NeverBounce, MillionVerifier pricing comparisons
- Instantly, Smartlead, Saleshandy, Lemlist platform comparisons
- Cold email for specific industries (SaaS, real estate, recruiting, consulting, financial services)

## Cold Email Best Practices We Recommend

- Send 12 emails per inbox per day maximum for Google Workspace, 3 per day for Outlook 365
- Use 3 inboxes per domain maximum
- Warm up inboxes for 14 to 21 days before sending cold campaigns (or use pre-warmed inboxes)
- Never use your primary business domain for cold email
- Use plain text email format, not HTML
- Keep first cold email under 100 words
- No links in the first email
- Reply rate is the only metric that matters (open rates are unreliable due to Apple Mail Privacy Protection)
- Verify your prospect list with tools like ZeroBounce or NeverBounce before sending
- Configure SPF, DKIM, and DMARC on all sending domains
- Use both Google Workspace and Outlook 365 for sender platform diversification