Email Warmup

Email warmup is the practice of starting a new sending domain or address at low volume and increasing it gradually over a period of weeks, so that mailbox providers build a positive picture of the sender before it sends at full scale. A brand-new identity has no history, and providers treat unknown senders with suspicion, so volume must be earned rather than assumed.

Why it matters for outbound

Skipping warmup is one of the fastest ways to kill an outbound program. Sending thousands of cold messages from a cold domain looks exactly like spam to a provider, and the domain reputation is poisoned before the campaign even begins. A proper warmup establishes the sender reputation that makes strong inbox placement possible. The patience it requires is precisely why so many in-house programs stumble out of the gate.

Outword warms and ramps every new sending foundation before client volume runs, so campaigns launch from a position of trust rather than risk.

How it works

• Authentication (SPF, DKIM, DMARC) is configured first.
• Sending starts at a small daily volume and increases on a measured schedule.
• Early sends favor engaged, low-risk recipients to generate positive signals.
• Volume scales only as reputation and deliverability hold steady.

The pace is dictated by results, not a fixed calendar. See our deliverability service for how warmup fits the broader sending plan.