Why You Cannot Blast a Migrated List
Warming up your account is one of the most critical steps brand owners skip when migrating to Klaviyo. If you import a database of 6,000 or 60,000 people from Mailchimp or Constant Contact and blast them with a heavy, image-stuffed template right out of the gate, mailbox providers will flag your domain immediately. That is a mistake.
Your sender reputation does not automatically transfer when you change platforms. You need to prove to Gmail, Yahoo, and Outlook that people actually want what you send. The fastest, safest way to do that is a focused two-campaign re-engagement sequence followed by immediate list cleaning.
Step 1: Build a Plain Text Re-Engagement Campaign
The first email you send from a new setup should never look like standard promotional marketing. It needs to look like a personal, human-to-human message. Plain text emails strip out the heavy HTML bloat and routinely hit the primary inbox because inbox providers treat them like standard correspondence.
Here is how to set up this first campaign:
- Sender name: Use a real person's name, such as Gavin Hewitson, rather than a generic brand handle or info@ address.
- Reply-to settings: If you do not want replies flooding your personal inbox, uncheck the default reply-to box and route incoming replies to your customer support address.
- Subject line: Put the offer right at the front. Something like "20% off your next order" works reliably well because numbers at the beginning of a subject line drive immediate engagement.
- Email body: Keep the copy brief and personal. Use a simple font like Helvetica, add a fallback tag (such as "Hi there" if first names are missing), and offer a genuine incentive with no complex terms attached.
If you are on Shopify, link your call to action using an auto-apply discount URL (yourdomain.com/discount/code). The less friction you create between the click and checkout, the better your conversion rate will be.
Step 2: Create Your Engaged Segment
Before launching the second email, you need to set up tracking for anyone who interacts with the first send. Our primary objective here is re-engagement, getting subscribers to open or click so mailbox providers recognise your sending domain as legitimate.
In Klaviyo, create a new dynamic segment with the following condition: What somebody has or has not done > Opened email at least once in the last 90 days. As soon as campaign one goes out, anyone who opens will automatically drop into this segment. This group forms the foundation of your future active sending list.
Step 3: Send Campaign Two to Non-Openers Only
Do not badger people who already opened your first email. Clone your initial campaign, rename it as campaign two, and add your newly created 90-day engaged segment to the "Do not send to" exclusion field.
Update the subject line to a short follow-up variation, such as "20% off: Still thinking it over?", while keeping the body copy simple and direct. This second email catches the people who missed the first send without annoying subscribers who already took action. You will see fewer opens than on round one, but it squeezes the remaining active users out of an otherwise stale list.
Step 4: Suppress Inactive Profiles After 48 Hours
Here is the hard truth: anyone who ignores two direct, high-value plain text emails in a row is dead weight. Keeping them on your active marketing list will destroy your domain reputation and unnecessarily inflate your monthly Klaviyo invoice.
Wait roughly 48 hours after campaign two finishes sending, then build a suppression segment:
- Condition 1: If someone is in your imported list.
- AND Condition 2: What someone has or has not done > Opened email zero times in the last 90 days.
Open the segment options, select "Suppress current members", and confirm. Suppressing is not deleting; their historical data remains in your account, but Klaviyo will no longer email them or bill you for them. The subscribers left behind are verified, engaged contacts ready for regular flow and campaign sends.
Final Thoughts
Warming up an account does not require months of complicated scheduling if you use a direct plain text strategy. Send two simple incentive campaigns, capture everyone who opens, and suppress the rest without hesitation. Protecting your sender reputation from day one is the only reliable way to guarantee your emails hit the primary tab.
If you are migrating platforms or setting up a brand-new store, let our team handle your technical deliverability and email architecture through our Klaviyo account setup service.
