Email Warm-Up
Gradually increasing sending volume from a new domain, IP address or mailbox so receiving providers can build a positive sender reputation.
A new sending domain or IP has no reputation, so sending full volume at once can push sales and marketing emails into spam or get them blocked, damaging campaigns and the domain for months.
A team sets up a secondary outreach domain with SPF, DKIM and DMARC, sends 20 emails per mailbox per day in week one, adds about 10 per day each week up to a cap of 50, and pauses increases whenever bounces exceed 2%.
Automated warm-up networks that trade artificial engagement may not reflect real recipient behavior and can breach provider terms. Warm-up cannot fix poor lists, missing authentication or unwanted content, and reputation fades after long pauses.
Mailbox providers treat new IPs and domains with little history cautiously and may throttle sudden spikes. A warm-up plan raises daily volume in steps, sends first to the most engaged recipients and monitors bounces, complaints and throttling. Amazon SES runs automatic warm-up for standard dedicated IPs over 45 days, SendGrid's automated schedule spans 41 days, and IPs idle for more than 30 days may need warming again. It underpins Email Deliverability for Cold Email programs.
Systems Architecture
Amazon Web Services — Warming up dedicated IP addresses (standard) in Amazon SES — https://docs.aws.amazon.com/ses/latest/dg/dedicated-ip-warming.html; Twilio SendGrid — Warming up an IP address — https://www.twilio.com/docs/sendgrid/ui/sending-email/warming-up-an-ip-address
