Send 50,000 emails on day one from a brand-new domain and mailbox providers will assume you're a spammer. Reputation is built gradually — a process called warming up. Done right, it takes two to four weeks and sets you up for long-term inbox placement.
Why warm-up matters
Providers like Gmail and Outlook watch how a new sender behaves. A sudden spike in volume from an unknown domain is the classic spam signature. A steady, growing volume of mail that people open and engage with is the signature of a legitimate sender.
A sample 4-week schedule
| Week | Daily volume | Focus |
|---|---|---|
| 1 | 50 → 500 | Your most engaged recipients only |
| 2 | 500 → 5,000 | Add recent, active subscribers |
| 3 | 5,000 → 25,000 | Broaden gradually; watch complaints |
| 4 | 25,000 → full volume | Reach your plan's daily limit |
Rules that make or break it
- Start with your best recipients. Opens and replies early on teach providers your mail is wanted.
- Keep volume consistent. No wild day-to-day swings.
- Watch the metrics. If complaints climb, slow down.
- Authenticate first. Warm-up on top of correct SPF, DKIM and DMARC — never before.
On higher-volume plans we offer managed IP warm-up, so the ramp is handled for you. See SMTP plans for details.
Patience here pays off for months. A domain warmed up properly keeps landing in the inbox; one that was blasted from cold can take a long time to recover — if it recovers at all.