What is Email Warmup?
Email Warmup is The process of gradually building sender reputation for a new email domain or IP.
Definition
Email warmup is the process of establishing trust with email providers before sending at volume. New domains and IPs have no reputation, so sending thousands of emails immediately triggers spam filters. Warmup tools simulate normal email activity: sending, receiving, and engaging with emails to build a positive reputation.
Why It Matters
Skip warmup, and your cold email campaigns die in spam folders. A properly warmed domain can send hundreds of emails per day with good deliverability. An unwarmed domain might get flagged after 50. Warmup takes 2-4 weeks but is essential for outbound sales.
Example
Before launching cold outreach, a sales team sets up Instantly to warm their new email domain. The tool sends and receives emails automatically for 3 weeks, building positive engagement signals that improve deliverability.
Tools for Email Warmup
Find the Right Email Warmup Tool
Not sure which tool fits your needs? Check out our curated recommendations: