How I warm up new cold email inboxes step by step

warmup_nate · 2026-03-18 · 2,340 views

Sharing my exact warmup process that I have used on over 200 inboxes. Most people either skip warmup entirely or do it wrong. Here is the day-by-day breakdown that consistently gets inboxes ready to send without suspensions.

Day 1-3: Manual sends only. Send 2-3 real emails per day to friends, colleagues, or your own accounts on different providers. Have them reply and engage. This establishes initial sending patterns that look human. Do not connect any warmup tool yet.

Day 4-7: Add warmup tool. Connect the inbox to your warmup tool (Instantly warmup or Smartlead warmup both work). Set warmup volume to 10-15 emails per day. The warmup tool sends and receives emails with other inboxes in the network, generating engagement signals that build sender reputation.

Day 7-14: Ramp warmup volume. Increase warmup to 20-30 emails per day. Keep sending 2-3 manual emails as well. Monitor your inbox placement using GlockApps or a similar tool. You want to see 80%+ inbox placement before moving to the next phase.

Day 14-21: Start cold sends. Begin sending cold emails at 5 per day while keeping warmup running. Monitor bounce rates and spam complaints closely. If bounce rate exceeds 2%, pause and clean your list. Gradually increase cold volume by 2-3 emails per day.

Day 21+: Full volume. Ramp to 15-20 cold emails per day for Google Workspace, or 20-30 for Outlook. Keep warmup running at 10-15 per day alongside your cold campaigns. Never turn off warmup completely.

The whole process takes about 3 weeks. I know that sounds slow, but I have burned dozens of inboxes by trying to skip steps. The 3-week investment protects your infrastructure long term.

The shortcut: PuzzleInbox pre-warmed inboxes skip this entire process. They arrive with sending history and established reputation. I have started cold campaigns within 24-72 hours of receiving pre-warmed accounts with no deliverability issues. If your time is worth more than the price difference, pre-warmed is the way to go.