How long does email warmup actually take? I tested 3 providers

warmup_tester · 2026-03-20 · 2,180 views

I was tired of getting different answers about how long warmup takes, so I ran a proper test. Bought inboxes from three different sources, set them all up at the same time, and measured inbox placement at every milestone using GlockApps. Here are the results.

Test 1: PuzzleInbox pre-warmed inboxes. Ordered 5 pre-warmed Google Workspace inboxes. Received them within 48 hours. Ran inbox placement test immediately on arrival.

• Day 1: 87% inbox placement
• Day 3: 89% inbox placement
• Day 7: 91% inbox placement
• Started cold sending on day 2. No deliverability issues.

Test 2: Instantly warmup on fresh inboxes. Bought 5 standard Google Workspace inboxes from a different provider. Connected them to Instantly and enabled warmup at 20 emails per day.

• Day 1: 34% inbox placement (expected — brand new accounts)
• Day 7: 58% inbox placement
• Day 14: 79% inbox placement
• Day 21: 86% inbox placement
• Started cold sending on day 14 at low volume. Safe to go full volume around day 21.

Test 3: Manual warmup (no tool). Bought 5 more standard inboxes. Warmed manually by sending 5-10 emails per day to real contacts and having them reply.

• Day 1: 31% inbox placement
• Day 7: 44% inbox placement
• Day 14: 62% inbox placement
• Day 21: 74% inbox placement
• Day 28: 82% inbox placement
• Not truly ready for cold sends until day 21+, and even then results were inconsistent.

Key takeaways:

• Pre-warmed inboxes are ready day 1. The premium is worth it if speed matters to you. The time savings alone justify the cost when you factor in 2-3 weeks of waiting.
• Instantly warmup works well but takes 14-21 days. This is the middle ground for teams who want to save money and do not mind waiting.
• Manual warmup is the slowest and most inconsistent option. Unless you have a very specific reason to do it manually, use a warmup tool or buy pre-warmed.

The bottom line: warmup is not optional, and it is not instant. Budget 2-3 weeks if you are warming manually or with a tool. Or pay the premium for pre-warmed accounts and start sending immediately. The choice depends on whether your time or your money is more constrained.