What is Email Warmup?
Email warmup is the process of gradually increasing sending volume on a new email account to build sender reputation. It's essential before running cold email campaigns—skip it, and you'll likely land in spam.
Why Warmup Matters
New email accounts have no reputation. Email providers are suspicious of accounts that suddenly start sending high volumes. Warmup builds trust gradually.
How Warmup Works
Week 1-2: Send 10-20 emails/day with high engagement
Week 3-4: Increase to 30-50 emails/day
Week 5+: Gradually scale to full volume (usually 50-100/day max)
Warmup Tools
Tools like Instantly, Lemwarm, and Warmbox automate warmup by exchanging emails with other accounts and generating positive engagement signals.
Best Practices
Never skip warmup on new accounts
Continue warmup even during active campaigns
Monitor inbox placement throughout
Don't warm up and cold email from the same thread
Frequently Asked Questions
How long should I warm up an account?
Minimum 2-3 weeks before sending cold email. Some providers recommend 4+ weeks for best results.
Can I skip warmup on an old account?
If the account has been active and has good reputation, you may need less warmup. But always check deliverability before scaling.