How Long Does Email Warmup Take? A Realistic Week-by-Week Timeline
inboxy team · · 3 min read
Short answer: two to four weeks for a new inbox, then keep warmup running for as long as you send. Rushing it is the most common way cold emailers burn brand-new domains. Here is what a realistic timeline looks like and what changes it.
Why warmup takes time
Inbox providers trust senders based on history. A new mailbox has none. Warmup builds that history with gradually increasing volume and positive engagement: opens, replies, emails marked important and moved out of spam. Providers want to see that pattern hold for a while, not for an afternoon.
A week-by-week schedule for a new inbox
| Week | Warmup emails per day | Cold emails per day |
|---|---|---|
| 1 | 5 to 15, ramping up | 0 |
| 2 | 15 to 30 | 0 |
| 3 | 30 to 40 | 10 to 15, if placement tests look good |
| 4 | 30 to 40 | 20 to 30 |
| 5 onwards | steady | 30 to 50 |
Before you start campaigns, run an inbox placement test. If you are not landing in the inbox yet, give it another week.
What makes it faster or slower
- Authentication. Without SPF, DKIM and DMARC, warmup barely helps. Set them up first.
- Domain age. Domains registered a few days ago warm more slowly. Buying domains a couple of weeks before you need them helps.
- Provider. Google Workspace and Microsoft 365 mailboxes start from a better position than cheap shared SMTP servers.
- Quality of engagement. Real inboxes that open, reply and rescue emails from spam build trust faster than bots that only send.
- History. Reviving a damaged domain takes longer than warming a clean one. Weeks to months, depending on the damage.
Warming an existing inbox
An inbox that has been used normally for months already has a reputation. If it has never sent cold email, a week or two of warmup at increasing volume is usually enough before campaigns. If it has been sending poorly, pause campaigns and warm it until placement tests come back clean.
Never switch warmup off
Once campaigns are live, cold emails bring little positive engagement. Warmup keeps adding it. Teams that turn warmup off after week three often see placement slide a month later. Keep it running at a steady level on every sending inbox.
How inboxy does it
inboxy warmup uses a private network of real inboxes that open your emails, reply, mark them important and pull them out of spam, ramping up gradually and adjusting to how your inbox responds. It works on inboxy mailboxes and on Gmail, Microsoft 365 and SMTP inboxes you already own, at $3 per inbox a month. See inboxy warmup.
