After you add a new and authenticated sending subdomain, it’s necessary to warm up the infrastructure. The warm-up requires sending fewer emails to highly engaged audiences right after adding the new subdomain, gradually increasing the volume, and relaxing the engagement constraints over a period of time.
During the warm-up period, the ISP (Internet Service Provider) assesses the emails to make sure the source is trustworthy, or in other words, that you are a reputable sender. Sending off too many emails, too early, will raise security concerns and might send emails to spam or block them completely.
The warm-up process
The warm-up process takes approximately 2-4 weeks but will vary depending on the sender and the ISP. During the warm-up process, emails must be prioritized due to the limited volume of emails to be sent.
Here are some guidelines:
First week
- Send only high-engaging flows, for example, welcome flows, abandoned cart, and browse abandonment
- Send campaigns only to those subscribers who are likely to engage best with your emails, since this establishes your reputation for mailboxes. Examples of segments you could leverage are engaged subscribers, such as those who ordered recently; top-tier customers, like the “VIP list"; loyalty customers (for users of our Yotpo Loyalty and Referrals program)
- Turn off win-back or re-engagement flows during the first week, or even for a couple of weeks.
After the first week:
After a week of high-engagement flows, you can begin sending a few campaigns to less engaged segments, such as those who ordered in the last 60 days, then 90 days, etc. Throughout the whole warm-up, send your best-performing, most engaging content to get the best results. If you send to inactive subscribers, you will risk having your emails moved to spam by ESPs (like Google, Hotmail, etc.).
Over the following weeks, monitor your performance and tweak your warmup accordingly. These are the recommended performance indicator targets before you progress between stages in the warming process:
| Performance indicator | Target value |
|---|---|
| Opens (unique) | ≥ 40% |
| Clicks | ≥ 2% |
| Hard bounces | ≤ 1% |
| Soft bounces | ≤ 2% |
| Unsubscribers | ≤ 0.3% |
| Spam reports | ≤ 0.08% |
If you see high bounce, spam complaint, or unsubscribe rates, stop sending and review the list you are sending to. If the list is outdated or has unengaged contacts, clean your list before sending the next campaign.
If you see low engagement rates, stop sending and review your domain warm-up audience. Ensure you are only sending to recently engaged contacts before beginning to send again.
Warm-up schedule
We recommend sending the following volume of emails for the first few weeks, and no more than one campaign per day. Here is an example for a merchant with 1M subscribers:
| Campaign # | Engagement window* | Number of emails |
|---|---|---|
| 1 | 30 | 500 |
| 2 | 30 | 800 |
| 3 | 30 | 2,000 |
| 4 | 30 | 3,500 |
| 5 | 30 | 5,000 |
| 6 | 30 | 7,500 |
| 7 | 90 | 10,000 |
| 8 | 90 | 17,500 |
| 9 | 90 | 25,000 |
| 10 | 90 | 35,000 |
| 11 | 90 | 45,000 |
| 12 | 90 | 60,000 |
| 13 | 90 | 80,000 |
| 14 | 90 | 130,000 |
| 15 | 180 | 180,000 |
| 16 | 180 | 230,000 |
| 17 | 180 | 280,000 |
| 18 | 180 | 360,000 |
| 19 | 180 | 460,000 |
| 20 | 180 | 580,000 |
| 21 | 180 | 700,000 |
| 22 | 180 | 840,000 |
| 23 | 180 | 1,000,000 |
*Engagement window refers to subscribers who have made a purchase or opened or clicked on a link in an email in the past <x> days. For example, for campaigns 2-4 you should include recipients who were engaged in the last 30 days, but you may also add recipients who were engaged only in the last 31-90 days.
Constructing your domain warm-up audience
A crucial factor of a successful warm-up is around the campaign's audiences. On a high level, there are a few ways to go about building the correct audience for your warm-up campaigns.
1. Using purchase data and previous segmentation data
If you have no email engagement data with us or from another ESP, you can still achieve good warm-up results by using past purchase data. In this method, you can select the audience for your first few campaigns by looking for:
- Subscribers who made a purchase in the past 30 (or even up to 90) days. You may choose to exclude those who made a purchase in the past 7 days, to prevent user fatigue.
These can be further tiered by spend and/or number of purchases. - Subscribers previously segmented into high-value segments like “VIP Customers”
- If you are also a Loyalty customer, you may leverage that by choosing your loyalty members, and even break it down by loyalty tiers
After a few campaigns, you will automatically switch to the next phase - using Yotpo Email Marketing engagement data.
2. Using Yotpo Email Marketing engagement data
Once you have accumulated enough email engagement data with Yotpo, you can use our rich segmentation capabilities to define the correct audience for each of the warmup stages. You will have to make sure your segments are not too wide, so you don’t vastly exceed the recommended audience size for each. For example, for your 5th campaign, if your segment for “clicked a link and/or made a purchase in the last 90 days” yields an audience of 7,500, you may narrow the 90 to achieve an audience closer to the desired 5,000.
3. Using engagement data from other (your previous) email marketing platform
If you have recent email engagement data from another email marketing platform, it is strongly recommended to harness it for your domain warmup. This requires the following process:
- Export engagement-based subscriber lists from your previous email marketing system, according to this logic:
- Engaged in the last 30 days
- Engaged in the last 31-90 days
- Engaged in the last 91-180 days
- Use a spreadsheet (or another tool) to break down the lists so they fit the campaign schedule requirements
- For example, if your “engaged in last 30 days” list size is 7,500, break it down to sub-lists of 500, 500, 1,000, 2,000, and 3,500.
- It will be easier if the lists do not overlap, meaning a subscriber will appear in one list at most
- Import those lists into Yotpo email marketing, giving the lists ‘meaningful’ names like:
| List name | List contents |
|---|---|
| Engaged_last_30_500_1 | 500 subscribers engaged in the last 30 days |
| Engaged_last_30_500_2 | 500 subscribers engaged in the last 30 days |
| Engaged_last_30_1000 | 1,000 subscribers engaged in the last 30 days |
| Engaged_last_30_2000 | 2,000 subscribers engaged in the last 30 days |
| Engaged_last_30_3500 | 3,500 subscribers engaged in the last 30 days |
- Create campaigns using one or multiple lists to build the correct audience from both engagement and volume POV