Email Warmup
Last updated March 25, 2026
Email warmup is the process of gradually increasing email sending volume from a new address to build sender reputation and avoid spam filters.
Email warmup is the process of slowly ramping up sending volume from a new email account while generating positive engagement signals like opens, replies, and inbox placement. This builds the domain and IP sender reputation that email providers use to determine whether your messages land in the inbox or spam folder. AI warmup tools automate this process by sending and receiving emails between accounts in a warmup network. Most cold email platforms like Instantly, Lemlist, and Smartlead include built-in warmup features.
Related Tools
Related Terms
Frequently Asked Questions
How long does email warmup take?
Typically 2-4 weeks to build sufficient sender reputation for cold outbound. Start with 5-10 emails per day and gradually increase to your target volume.
Do I need to warm up every new email account?
Yes. Every new email address should be warmed up before sending cold outreach to avoid landing in spam.
Can I warm up email accounts for free?
Most cold email platforms include warmup in their paid plans. Standalone free warmup tools exist but are less reliable than integrated solutions.