Why is there a warm-up phase?
New email domains require a so-called “warm-up phase” to establish a positive sender reputation with email providers like Gmail, Yahoo, or Outlook. This phase ensures your emails land in inboxes rather than spam or promotional folders.
Think of it as an introduction period: you gradually and professionally present yourself to email providers to make a good first impression. If you skip this phase or send immediately to your entire list, you risk being flagged as spam right away.
Important: Major promotions or sales aren’t recommended during the warm-up phase. The goal is to build an excellent sending reputation—not maximize immediate revenue. Initially, focus on high-quality, trust-building content.
How does the warm-up phase work?
The warm-up typically takes place over five to ten campaigns, beginning with a small recipient count and gradually increasing with each campaign.
Our AI automatically selects the ideal number of recipients for each newsletter. Here’s how that might look:
Newsletter | Number of Recipients |
1 | 1,500 |
2 | 3,000 |
3 | 5,000 |
4 | 8,000 |
5 | 12,000 |
6 | 18,000 |
7 | 27,000 |
8 | 40,000 |
Best practices during the warm-up phase
Send two to three newsletters per week during the first two weeks, ideally spacing them two or three days apart.
Use varied content, though the recipients may overlap. Our AI-driven warm-up automatically selects the best recipients from your list—those most likely to engage with your emails, achieving high open and click rates.
This strategy demonstrates to providers that your emails offer value, greatly improving your long-term deliverability.
Alternatively, you can extend the warm-up phase to two or three weeks by sending only one or two emails per week.
Tip: Start creating email sequences as soon as possible, as these significantly support the warming process.
Important notes
Don’t skip: You can’t skip the warm-up phase—once you have a negative reputation, it’s extremely difficult to repair.
Automate: Our system handles recipient selection automatically, ensuring optimal results.
Avoid duplicate content: It’s intentional that top recipients receive multiple emails with different content, boosting your sender reputation.