What the providers actually say
Google's email sender guidelines do not use the phrase warm up, but they describe it: start with a low sending volume to engaged users and slowly increase over time, avoid sudden volume spikes if you have no history of large sends, and send at a consistent rate rather than in bursts. Google says the right pace depends on how much you send, how often you send, and recipient feedback, and that if mail is deferred or bounced you should reduce volume until errors drop, then increase slowly again.
Yahoo's sender best practices focus on authentication, a spam rate below 0.3%, one-click unsubscribe and honoring opt-outs within 2 days. They do not set out a ramp. Treat any specific schedule you see, including ours, as an example.
Before the first send
- Authenticate the domain in your email tool. MailerLite, for example, provides DKIM, SPF and verification records and allows unauthenticated sending only during its 14-day trial.
- Publish a DMARC record; p=none is acceptable to Google and Yahoo for bulk senders.
- Use a DKIM key of at least 1024 bits; Google recommends 2048 if your provider supports it.
- Set up Google Postmaster Tools for the domain so you can see the spam rate as volume grows.
- Confirm each message carries one-click unsubscribe headers and a visible unsubscribe link.
- Send a test to your own Gmail and Yahoo addresses and check that authentication passes in the headers.
Order your list by engagement
Google's advice to start with engaged users means your first sends should go to the people most likely to open and least likely to complain. On a new list, that usually means the most recent signups. On an imported list, it means readers who opened or clicked recently in your old tool.
Split the list into tiers before you start: tier A signed up or engaged in the last 30 days, tier B in the last 90 days, tier C older. Leave anyone you have not emailed in two years out entirely; MailerLite's anti-spam policy does not allow those addresses.
Example ramp for a 4,000-subscriber import
This is an illustrative schedule for a newsletter sending twice a week, not a provider rule. Move to the next step only if the stop rules below are clear. A weekly sender would spread the same steps across more weeks.
| Send | Who receives it | Approximate volume | Move on only if |
|---|---|---|---|
| 1 | Tier A, most recent first | 300 | No deferrals; complaints under 0.1% |
| 2 | All of tier A | 600 | Same as above |
| 3 | Tier A plus first part of tier B | 1,000 | Bounces low; Postmaster spam rate under 0.1% |
| 4 | Tier A plus most of tier B | 1,600 | Same as above |
| 5 | Tiers A and B | 2,400 | Same as above |
| 6 | Add the first part of tier C | 3,200 | Complaints still under 0.1% |
| 7 | Full list | 4,000 | Keep sending at a steady rate |
Stop rules and the numbers behind them
Pause the ramp and hold or reduce volume if any of these appear. A worked example: 2 complaints on a 900-message send is about 0.22%, more than double Google's 0.1% target and above MailerLite's 0.2% suspension trigger, so you would hold at the previous step and look at which tier those complaints came from.
| Signal | Threshold | Source | What to do |
|---|---|---|---|
| Spam rate | Aim below 0.1%; never reach 0.3% | Hold volume; drop the least engaged tier | |
| Spam rate at Yahoo | Below 0.3% | Yahoo | Same as above |
| Complaints in MailerLite | More than 0.2% may trigger suspension | MailerLite Anti-Spam Policy | Hold and review list source |
| Bounces in MailerLite | More than 5% may trigger suspension | MailerLite Anti-Spam Policy | Clean invalid addresses before the next step |
| Deferrals or temporary errors | Any increase | Reduce volume until errors drop, then increase slowly |
After the ramp
Warm-up is not a one-time event. Google ties the pace of increase to recipient feedback and consistency, so a sudden jump later, such as a big promotion to the whole list after months of small sends, carries the same risk. Keep your schedule steady, keep removing long-inactive readers, and repeat a shorter ramp if you change sending domain or provider.
Questions before you decide
Is there an official warm-up schedule?
Not in the Google and Yahoo pages reviewed for this guide. Google describes principles, such as starting low, increasing slowly and avoiding spikes, rather than a fixed schedule. Yahoo's best-practices page does not cover ramping.
Does sending weekly change the ramp?
Google says daily sending allows faster increases than weekly sending. With a weekly newsletter, the ramp stretches across several issues.
Who counts as a new domain for Gmail?
Google's FAQ treats a domain as new for its bulk-sender enforcement if it has not sent more than 5,000 emails a day to personal Gmail accounts since January 1, 2024.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Google: Email sender guidelines Accessed 29 Oct 2026
- Google: Email sender guidelines FAQ Accessed 29 Oct 2026
- Yahoo Sender Hub: Best practices and requirements Accessed 29 Oct 2026
- MailerLite Anti-Spam Policy Accessed 29 Oct 2026
- MailerLite Help: Domain authentication Accessed 29 Oct 2026
Sources link directly to providers. Product buttons may use separately labeled affiliate links. Read our disclosure.