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How to warm your authenticated domain

Overview

When you authenticate a new sending domain, you have no reputation as a marketing email sender. Inbox providers have developed various mechanisms to protect their users from spam, including carefully monitoring emails sent from new domains.

When you warm your domain correctly, you show inbox providers that your emails are safe enough to reach the inboxes of their users.

Warming your new domain means sending high-quality content to small groups of highly engaged contacts and exponentially increasing the size of your audiences when open and click metrics are good until you have successfully sent to all of your 90-day engaged contacts. This process is the basis of your new sending reputation.

Read on to learn about Sendlane's approach to domain warming.

In this guide


Domain warming process

Domain warming cannot be effectively accomplished by following prescriptive plans developed before sending begins. To correctly warm your domain, you must react to each send's metrics.

Your warming may go perfectly for the first five sends only to see open and click metrics tank on send six. If you've developed a strict calendar of sends with pre-configured audiences and try to push through "just one" bad send, you might severely damage your sending reputation or, in extreme cases, burn your domain.

It is not possible to know, with certainty, exactly how your domain warming journey will go before you get started. You may finish warming your engaged contacts a week earlier than you roughly expected, and you can just as easily finish a week or two later (or longer).

Step One: Note your baseline metrics

Log in to your previous email provider and record the metrics you achieved for subscriber volume, open, click, and conversion rates. Keep this information somewhere safe! Your baseline metrics can be used to help diagnose deliverability issues in the future.

Open and click rates will vary during warm up. After enough clean sending, generally one month, metrics should stabilize.

When your account is fully warmed, you should see metrics that meet or exceed the baseline from your previous ESP.

⚠️ Update your Sendlane account's attribution settings to match your previous ESP

If attribution settings in Sendlane differ from the settings you used in your previous ESP, you will not be able to evaluate attribution effectively. Update your account's attribution settings before warming starts.

Step Two: Prepare warming content

You should use evergreen content for domain warming emails. Check out the Sendlane marketing team's comprehensive guide to designing great evergreen content.

While you can't pinpoint the exact date of each warming send in advance, preparing enough campaigns in Sendlane to cover the number of sends your warming process will likely take is a great idea. Having your campaign content ready to go before you start sending means you can focus on analyzing your sends' performance without worrying about creating a campaign for the next send.

Step Three: Choose an audience preparation method

Domain warming means sending successfully to cohorts of contacts who have engaged with your brand at least once in the last 90 days. Contacts not engaged for more than 90 days should not be sent to during domain warming.

Warming audiences (recipients of each warming campaign) should ideally be prepared using your existing email service provider's engagement segmentation mechanism to create up to date segments based on contact engagement.

If you no longer have access to your ESP or expect to lose access to it during the warming process, you can also use a bulk exported list of your contacts that includes their last open and click dates to create warming audiences. This option poses risks to your sending reputation due to the scant and increasingly stale engagement data; you unequivocally should not use this method if you can create active segments in your previous ESP.

Whichever method you choose, it should be the method you use for the entire warming process. Switching between methods is likely to harm your sending reputation.

Step Four: Prepare your first send

Your first warming send should have an audience of 1,500 of your most engaged subscribers.

Initial warming audiences of less than 1,500 subscribers might suggest to inbox providers that you are trying to bypass their bulk email analysis, and inbox providers generally consider sending to more than 1,500 subscribers on a new sending domain to indicate future spam-like behavior.

It's important to start at 1,500; no more, no less. While your domain won't be irretrievably burned if you send to 1,499 or 1,501 subscribers, we have seen consistent success with 1,500 and highly recommend staying as close to that number as possible.

Follow the steps outlined in your chosen audience preparation method below. Remember to use your previous ESP's segmentation if you have access to it. You should NOT use the bulk export method if you will have access to your previous ESP for as long as your warming process takes.

Using previous ESP's segmentation

You will complete the following process before every send, ideally 24 but no more than 48 hours before your next send. For your first send, complete the following 24 hours before you want to send (make sure to plan your first send's preparation around list review working hours):

  1. Create a segment in your previous ESP of your most engaged contacts: generally, people who have clicked a link in an email in the past one to three days.
  2. Export the segment to .CSV
  3. Ensure your export meets Sendlane's contact import requirements
  4. Import your exported segment into Sendlane as a list
  5. Watch your inbox for an email from the Sendlane compliance team that will either inform you that your list has been approved or ask for additional information about your list
  6. Set up an email campaign
  7. Send!
Using bulk export of all contacts

You will complete steps 1-9 before your first send, then repeat steps 4-9 for each subsequent send using subsequent rows of contacts (mark the rows you've sent to on your spreadsheet to make future list building easier). 

Make sure to plan your first send's preparation around list review working hours

  1. Create a segment of contacts who have clicked or opened an email in the last 90 days
  2. Export the segment to .CSV
  3. Open the .CSV using Excel or Google Sheets and sort the last click column in descending order so that the row with the most recent click is at the top
  4. Select and copy the first 1,500 rows
  5. Paste the rows into a new sheet
  6. Export the sheet as .CSV
  7. Ensure your export meets Sendlane's contact import requirements
  8. Import your exported segment into Sendlane as a list
  9. Watch your inbox for an email from the Sendlane compliance team that will either inform you that your list has been approved or ask for additional information about your list
  10. Set up an email campaign
  11. Send!

Step five: Review your first send's metrics

24 hours after every send, review your campaign's report. Use the following guidelines for overall open and click rates to guide subsequent sends.

  • 🟢 ≥ 30-50% open rate or ≥10% click: Strong. Barring other issues, you can increase your next send's audience size by 1.4x or 40%.
  • 🟡 20-29.9% open rate or 5-10% click rate: Relatively strong. Barring other issues, you can increase your next send's audience size by 1.4x or 40%, but watch your next send's metrics closely to ensure opens don't decrease to below 20%.
  • 🟠 10-19.9% open rate or <5% click rate: Showing signs of problems. For your next send, review your content and optimize, send to a similarly sized group, and watch your next send's metrics closely
  • 🔴 <10% open rate or <2% click rate: Engagement is too low, and your sending reputation is in danger. On your next send, keep your audience size the same and only include contacts who have opened or clicked during warming.

You should also monitor inbox specific open and click rates. If you notice one provider's metrics decreasing, reduce the amount of contacts using that provider for your next send until the metrics stabilize.

Step six: Prepare subsequent sends

If you're using your previous ESP to create segments for each new send, repeat the process in Using previous ESP's segmentation until you have successfully sent to all your 90 day engaged contacts.

If you used a bulk export to create your warming send's audience, repeat steps 4-9 in Using bulk export of all contacts until you have successfully send to all your 90 day engaged contacts.

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Domain warming ends when you've sent to your 90 day engaged contacts because in the vast majority of cases, contacts who have not engaged with your emails in the past 90 days are unlikely to engage in the future.

We highly recommend not attempting to re-engage older contacts. Resources and energy spent on re-engagement tactics are often better spent on optimizing for engaged contacts. If you must re-engage older contacts, follow these guidelines.

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