Email Warm-Up

Email warm-up is the practice of gradually increasing the volume of emails sent from a new or dormant email account or domain to establish a positive sender reputation with email service providers like Google and Microsoft.

This process is critical for any outbound sales team because email providers track sending behavior closely. A brand-new domain that suddenly sends hundreds of cold emails will get flagged as spam almost immediately. Warm-up teaches email providers that your domain is legitimate and that recipients engage with your messages.

A typical warm-up process works like this: during the first week, you send 10-20 emails per day to contacts who will open and reply. Each week, you increase volume while maintaining strong engagement metrics. Most warm-up takes 3-6 weeks before a domain is ready for full outbound volume.

Many teams use automated warm-up tools that send emails between a network of inboxes, generating opens and replies to simulate real engagement. While this works, it is important to also send real emails to real contacts during warm-up — providers are getting better at detecting artificial engagement patterns.

Practical tips: always set up SPF, DKIM, and DMARC records before starting warm-up. Use a dedicated subdomain for outbound (e.g., outreach.yourcompany.com) to protect your primary domain. And never rush the process — a few extra weeks of warm-up saves months of deliverability headaches.

Teams running SDR operations at scale typically maintain multiple warmed-up domains to distribute sending volume and reduce risk.