How to ramp and warm your sending infrastructure

You will learn

You will learn how to choose the right process to warm or ramp your email volume on Klaviyo to help you reach your subscribers.

Any new sender must warm up their sending infrastructure when moving to a new email service provider, like Klaviyo. Warming typically involves building sending reputation (i.e., warm up), and gradually increasing email volume (i.e., ramp up) that is sent from a new domain or sending IP. Warming is often a byproduct of ramping, as all sends and related email performance contributions to sending reputation and deliverability. Learn more about the difference between warming and ramping.

In this guide, we will walk through each step in the warming process as it relates to your particular use case.

How to choose your warming process (if applicable)

Depending on what type of Klaviyo customer you are, if you have engagement event data, are using a new domain, and other potential considerations, your warming process may differ. Use the guidance below to decide which process you should follow.

Use case with warming or ramping process to follow

Klaviyo customers moving to a dedicated sending domain

• Existing Klaviyo customers moving to a dedicated sending domain, DO NOT have to warm your infrastructure again, as long as you have:
  • a domain that has been registered for at least 30 days AND
  • you’ve used the domain to send email already (e.g., you used this domain in the past with a prior email service provider or with Klaviyo in your from address)
    
    
• New Klaviyo customers follow the standard guided warming process below, if you are a new Klaviyo customer (either on a shared or dedicated domain) and:
  • have engagement data (i.e., opens, clicks, etc.) OR
  • are using a Klaviyo-built integration that syncs open and click events
    
    
• Newly registered domains put in use by new or existing customers should also follow the standard guided warming process, if the newly registered domain was created and registered within the last 30 days and or never used to send email).

Klaviyo customer without engagement events or data
You should use the platform introduction process, if you:

• do not fit into any of the use cases above OR
• are not using a Klaviyo-built integration that syncs open and click events OR
• simply do not have any engagement data that you are bringing over to Klaviyo (e.g., you only have date-based properties such as “last opened,” “last clicked,” etc.).

Standard guided warming process

If you fall into the category of our standard guided warming process, you may see notifications appear in your account as you ramp up with Klaviyo or once you meet the qualifications for warming (see below). During guided warming, a banner will appear in your campaign editor instructing you on best practices based on the stage of warming you are in.

To see guided warming notifications you must meet the following qualifications:

• Are a new account or an account that recently moved to a dedicated infrastructure
• Have at least 5,000 active profiles
• Have engagement event data synced to Klaviyo; for new customers. This can be synced from a previous ESP using one of our pre-built integrations.

If you do not initially qualify for full guided warming, you may still see notifications from Klaviyo prompting action for optimal success as you warm your account. For more information on guided warming, head to our article About guided warming.

1. Migrate historic engagement data

If you are warming your infrastructure due to moving to Klaviyo from another email service provider (ESP), it's important to take historic engagement data into account so that you accurately build engaged segments. 

This will allow you to introduce your new relationship with Klaviyo to the mailbox providers (MBPs) in a positive manner, as you will contact those that are already engaged with your brand, while limiting contact with those that may not want to hear from you.

Klaviyo has guides for migrating your data over from several different ESPs to facilitate the import of engagement criteria, including:

• Mailchimp
• Bronto
• Constant Contact
• Campaign Monitor
• Exact Target
• Listrak
• Sailthru

2. Create engaged segments for sending campaigns
Sending to highly engaged segments over time helps to prevent any single low-performing message from damaging your overall deliverability. If you are using a brand new domain that has never been used in sending email, remember that these initial sends can greatly impact your reputation.

Create segments based on engagement over 30, 60, 90, 120, and 180 days. You will use these when sending over time, starting with your 30 day segment. If you send to inactive subscribers, you risk having your emails moved to spam by MBPs (e.g., Google, Hotmail, etc.).

If you're just starting out with Klaviyo or migrating from another platform, leverage historic engagement data from your previous platforms to create these segments.

However, if you attempt to send a campaign to more than the recommended amount of recipients during warming, Klaviyo will alert you with a warning, encouraging you to review this guide and lower the recipient count of your campaign. For your first campaign, we recommend that you send to fewer than 10,000 recipients. This recommended recipient count will then grow dynamically as you send to more people over time, so the warning will adjust accordingly, as shown below.

3. Send campaigns to engaged segments
As you start to engage your 30, 60, 90, 120, and 180 day segments, you will want to aim for the open rates listed in each section below. However, it’s important to note that open rates may vary per sender and industry, so your focus should follow the guidance below along with attaining as high as possible engagement for your specific business. Learn more in our resource on monitoring deliverability performance.

30 day segment (initial warming and daily sending)
For your first send, aim for open rates of above 30% if possible. Getting an open rate this high will require sending to a segment of anyone who has clicked in the last 30 days, or those who subscribed within the last 15 days.

If your 30 day engagement segment results in a very large group of profiles, consider the following:

• Use smart send time to divide up sends
  By using Smart Send Time, your email sends will be automatically divided up and sent over the course of 24 hours. This will help you send to smaller groupings of subscribers and continue to warm your IP. Additionally, you will learn the best time of day to send to these subscribers in the future. (Note that Smart Send Time requires at least 12,000 subscribers in Klaviyo).
• Use batch sending to divide up sends
  Use batch sending to break up your email sends into smaller groupings of users.
• Take random samples of the engaged segment
  Taking a random sample of your segment will allow you to break larger sends into smaller groups.

Be conservative in your sending during this time and strive for as high of engagement as possible. For the first two weeks, focus on sending to the 30 day engaged segment. As long as your open rates remain above 20% you can relax the engagement criteria to 60 during weeks 3 and 4. After four weeks of sending with at least 20% open rates, you can relax the engagement criteria to 90 days. Continue with this strategy for two weeks at a time, and then further relax your engagement criteria. Your optimal engagement timeframe will vary depending on your individual business needs.

If your email open rates dip below 20%, continue sending to the current engagement segment, but pause ramp up to the next engagement segment. This may be a sign that your reputation is being negatively affected and you may need to strengthen your sender reputation.

60 day segment (for sending up to 3 times a week)
After a two weeks of sending to a 30 day engaged segment and consistently seeing high engagement, you can broaden your audience to a 60 day engaged segment as long as this doesn’t substantially increase the size of your sending list. Remember to stay conservative in the number of email sends during this time. Make sure your open rates stay above 20%. If they do not, return to your 30 day segment.

90 day segment (for sending up to 2 times a week)
If you can continue to broaden past 60 days, create a 90 day engaged segment instead. Again, make sure open rates are 20% or higher, and if not, then tighten your timeline.

120 day segment (for sending weekly)
After sending to your 30-90 day engaged audiences for a few weeks, relax your engagement criteria to 120 or 180 days. Again, strive for high open rates above 20%.

180 day segment (for sending monthly)
Follow the below to expand to your 180 day engagement. Tighten to 120 days or lower if engagement falls below 20%.

4. Turn on high engagement flow emails

Once you have created and sent to all your engaged segments, it’s now time to turn on your automations or flows. It’s critical that you only turn on flows that have historically performed well.

There are three types of flows that you should review for high engagement:

1. Welcome series

2. Abandoned cart

3. Browse abandonment

Determining your high engagement flows
We recommend reviewing your previous performance on these particular flows, and only turning them on if they have performed well. Below are the numbers you should look for in terms of high engagement and well-performing flows:

• Open rates above 40%
• Click rates above 1%
• Unsubscribe rates below 0.1%
• Complaint rates below 0.1%

What to do if you do not have high performing flows
If your flows have not historically performed well, follow the below guidelines on when to turn them on:

1. Welcome series: after 2 weeks of sending campaigns from Klaviyo
2. Abandoned cart: after 30 days of sending campaigns from Klaviyo
3. Browse abandonment: after 30-60 days of sending campaigns from Klaviyo

High risk flows to send later
Winback, re-engagement, and sunset flows may be high risk flows to turn on, as they typically see low engagement anyhow. It is recommended not to begin with these flows below until ramping and warming are both fully complete.

For more details on deploying these flows, see the below resources:

• Creating a winback flow
• Creating a sunset flow
• Creating a re-engagement flow

5. Monitor your performance
These tools will help you monitor your performance as you warm your sending domain:

• Review flow analytics
  Check back periodically on your flows’ open, unsubscribe, and spam complaint rates to gauge the engagement with these emails.
• Monitor campaigns using the trends report
  This report will show you changes over time in all the important email engagement metrics. In particular, monitor the graph showing Marked as Spam and Hard Bounce rates, and look into campaigns that are responsible for any spikes in behavior. Learn more in our guide to monitoring your deliverability and email performance.

Platform introduction process

If you cannot use standard guided warming (e.g., only have date-based data properties like “last open” or “last click”), or have no engagement data available, you will use a modified version of guided warming (i.e., platform introduction). Platform introduction does not require that you have historical engagement data. Instead, it is a manual process that involves creating segments or using random sampling.

Platform introduction starts out with smaller audiences, allowing you to gradually open up volume over the course of about 30 days. In the chart below, the second column denotes this subscriber size or volume you should use daily.

After your first send, you will begin to have Klaviyo engagement data in the platform. For best performance, it's suggested to include engaged segments during this ramp up period.

The two guides below outline the following:

• recommended daily sending volumes (second column)
• and suggested engagement segments once available (third column)

The two guides below provide details for brands that either send daily vs. brands that send weekly.

Daily senders suggested email volume and engagement

Weekly senders suggested email volume and engagement

Additional resources

• Understanding self-serve domain authentication
• How to create an engaged segment
• How to monitor deliverability performance