How to warm up a new domain for cold email — without a warm-up network

A new domain has no reputation. Receivers do not trust it, and the first few hundred messages decide what they will think of it for months. “Warm-up” is the process of earning that trust. The popular way to do it is to join a network where thousands of mailboxes send automated messages to one another and mark them as not-spam. It works, sort of, and it has three problems: the traffic is fake, Google has said it treats such networks as a signal, and every mailbox in the pool shares the reputation of the worst one. This guide is the other way.

Before you send anything

1. Buy a separate domain. Never warm up your primary company domain for cold email. Use a close variant (yourcompany-hq.com, tryyourcompany.com) and set it to redirect to your real site so a curious recipient lands somewhere real.
2. Authenticate it fully. SPF, DKIM signed with your own key, DMARC at p=none with reporting. Confirm all three on a real message, not just in DNS. DMARC ramp here.
3. Create two or three mailboxes, not twenty. Real names, real photos, a signature, a filled-in profile. Receivers look at whether a mailbox behaves like a person's.
4. Let the domain age. Two to four weeks of existing before sending is worth more than any tool. Use the time to set up the mailboxes, sign up for a couple of newsletters, and reply to a few real emails.

The ramp: four weeks, per mailbox

These caps are per mailbox per day, and they assume bounces stay under 2% and complaints stay at zero. If either breaks, hold the cap where it is until the numbers recover; do not push through.

Week	Daily cap	Who to send to	What to watch
1	5 → 10	Warm contacts: customers, partners, people who will reply	Replies. You want conversation, not just delivery.
2	10 → 20	Verified cold list, best-fit segment only	Bounce rate. Anything over 2% stops the ramp.
3	20 → 30	Broader cold list, still verified	Postmaster Tools spam rate and domain reputation.
4	30 → 40	Normal sending	Reply rate trend. Falling replies at rising volume means slow down.

Forty a day per mailbox is a sensible steady-state ceiling for cold email from a Google Workspace or Microsoft 365 mailbox. It is well under provider limits on purpose: the goal is reputation, not throughput. If you need more volume, add mailboxes and domains and ramp each one — do not raise the cap.

The signals that decide when to raise the cap

• Bounce rate under 2% across the last few hundred sends. Above it, stop and re-verify the list.
• Zero complaints in Google Postmaster Tools. One complaint at low volume is a large percentage; treat it as a hold.
• Reply rate holding as volume rises. A reply rate that halves when you double volume means the extra sends are landing in spam.
• No temporary failures (4xx responses) from Gmail or Outlook. These are the first sign of rate limiting and arrive before any bounce.

Behaviour that speeds warm-up

• Send inside the recipient's working hours, spaced across the day rather than in a burst.
• Plain-text messages, one link at most, no images, no tracking pixel.
• Reply to every reply, quickly, from the same mailbox. Real conversation is the strongest positive signal a receiver can see.
• Send some genuinely wanted mail from the domain — a partner update, an introduction — so its history is not 100% cold outreach.

When to stop and start over

If the domain lands on Spamhaus or a major DNSBL, or Postmaster Tools shows “bad” domain reputation for more than a week, the cheapest fix is usually a new domain. Reputation recovery on a burned domain takes months and often never completes. This is the argument for never using your primary domain, and for keeping several outbound domains at modest volume rather than one at high volume.

How Quotarider does this for you

Every new mailbox in Quotarider starts on a reputation ramp: the daily cap begins low and rises only while bounces, complaints and reply rate stay inside thresholds. The Sequence Guardrail reads the same signals before each send and can delay or pause a step when one moves the wrong way — and the cap you set in settings can never exceed what the ramp allows. There is no warm-up network. The traffic that builds your reputation is your own, to people who might actually reply.