Domain warming

A new domain has no sending reputation. Ramp slowly or you'll land in spam.

The rough schedule

Week	Max sends/day	Focus
1	10-20	Only to recipients likely to engage (existing customers, warm contacts)
2	50-100	Widen to qualified prospects; watch bounce and complaint rate
3	200-500	Normal volume for most agent workloads
4+	1000+	Steady-state if you're actually sending that much

What actually matters

Volume ramping is the visible part. The invisible part is engagement. ESPs look at:

• Reply rate — did anyone reply? Replies are the strongest positive signal.
• Bounce rate — did the address exist? Under 2% is the safe ceiling.
• Spam complaints — did recipients click "report spam"? Anything over 0.1% is catastrophic.
• Open rate — lesser signal, and you can't rely on it with Apple Mail Privacy Protection blunting tracking pixels.

The fastest way to warm a domain is to send mail that gets replied to. That's exactly the agent use case — if your agent is doing useful work, the warming takes care of itself.

The one rule

Never send a cold blast to a freshly-added domain. 1000 unverified recipients on day one is the fastest way to get your domain flagged.