Author
Huzayfa Majeed
Founder, WarmInboxes · Huz on the rest of this site
Huzayfa Majeed founded WarmInboxes and runs the cold email agency it was built for, which sends more than a million cold emails a month on the same infrastructure WarmInboxes sells. He is an Instantly Certified Expert, a Smartlead Partner, Clay Verified and a PlusVibe Technology Partner, and he built the free deliverability tools on this site so the checks his team runs before every campaign are public.
Certifications
- Clay Verified
- Instantly Certified Expert
- PlusVibe Technology Partner
- Smartlead Partner
Studies and playbooks
- Every placement test we ran on prewarmed inboxesEvery new batch of prewarmed inboxes is seed-tested before it ships, and only stock clearing 95% is deployed. Seven tests, 333,731 messages scored, published whole — a live read on how hard inboxing got through 2026. Every results screen is on the page.
- A study of top-level domains by sends3,415,449 sends split across five TLDs and scored against Google’s permanent domain-reputation verdict. .link drew it 16 times more often than .com, and .org twice as often — and the gap holds inside a single client, where the copy and the list are the same. The TLD you buy predicts this better than anything else we measured, and unlike a blocklist listing it costs replies.
- Does a SURBL listing actually hurt cold email? We tested 2,817 sending domainsA DNS sweep of every live sending domain, not a sample. 43.3% were listed, and reply rate barely moved: 1.14% to 1.16%. Includes the three mechanisms we diagnosed SURBL grouping domains on — shared keyword, redirects to one master, shared nameserver zones — and the fix for each.
- The 2026 Inboxing PlaybookA clean operator guide for building cold email infrastructure that survives longer, routes smarter, and keeps campaigns out of spam.
- The Ultimate Liquid Syntax Guide: Hidden Ways To Personalize Cold Emails Using Your SequencerHow to make cold emails feel timely, human, and relevant at scale with Liquid syntax, smarter conditional logic, and better sending context.
- How to Avoid the SPAM Plague in 2026: The Complete List Verification, ESP, ESG & Role Segmentation PlaybookA field-tested cold email segmentation system for cleaner lists, better inbox routing, sharper persona-based copy, and higher reply rates before you ever launch.
Recent articles
- SURBL Is Mass-Listing .info Domains on Microsoft and Azure - What Happened and What To DoJun 24, 2026
- How to Get Free Domains for Cold Email in 2026: The Complete GuideJan 15, 2026
- Complete Guide to Prewarmed Email Inboxes in 2026Jan 15, 2026
- Where to Buy Pre-Warmed Emails According to Reddit (2026)Jul 25, 2026
- Are Pre-Warmed Inboxes Worth It? An Honest Evaluation From Someone Who Sells ThemJul 24, 2026
- How to Buy Pre-Warmed Email Accounts Without Getting BurnedJul 24, 2026
- Pre-Warmed vs New Inboxes: Which Should You Buy for Cold Email?Jul 24, 2026
- Pre-Warmed Inbox vs Email Warmup Tool: What Each Actually DoesJul 24, 2026
- Cold Email Sending Limits Per Inbox: The Numbers That Keep You SafeJul 24, 2026
- How Long Does Email Warmup Take? The Real Timeline for 2026Jul 24, 2026
- How to Skip Email Warmup and Start Sending Today (the One Way That Works)Jul 24, 2026
- Listed on UCEPROTECT Level 3? Here Is Why It Almost Never Matters for Cold EmailJul 22, 2026
The free tools
Every deliverability check the agency runs before a campaign is public and free on this site, and callable by an agent through the MCP server. They state what they cannot see rather than inventing a score.
Browse the tools