If your Klaviyo revenue is falling while your send volume stays flat, do not rewrite your emails yet. Check whether they are reaching the inbox.
Deliverability is the part of your email marketing system nobody sees until it breaks. Here is the setup that keeps it healthy, in the order we check it.
Step 1: Authenticate your sending domain
Gmail and Yahoo decide whether to trust a message by checking three settings on your domain.
- SPF lists the tools allowed to send email as you.
- DKIM adds a signature to every message so it cannot be faked.
- DMARC tells inboxes what to do with messages that fail the first two.
Since the 2024 sender requirements from Gmail and Yahoo, bulk senders are expected to have all three in place. A DMARC record can start at monitoring only (p=none), which lets you see who is sending as you before you enforce anything. Moving to enforcement is the later, safer step. We looked at how many brands skip it in our check of 154 DTC brands.
Step 2: Set up a branded sending domain in Klaviyo
By default, Klaviyo sends from a shared domain. A branded sending domain means your mail is signed with your own domain, so your reputation is yours and not shared with strangers.
In Klaviyo, go to Settings, then Domains, and follow the branded sending domain setup. Klaviyo gives you the exact DNS records to add. Add them at your DNS host, then verify. Use a subdomain you control, not a free mailbox address, as the From address.
Common failure points: records added to the wrong DNS host, an old SPF record that already exists and needs merging rather than duplicating, and a From address that does not match the authenticated domain.
Step 3: Meet the complaint and unsubscribe rules
- Keep your spam complaint rate low. Google’s published guidance is to stay under 0.3 percent and ideally well below 0.1 percent. Check it in Google Postmaster Tools, which is free.
- Make unsubscribing easy. Bulk senders are expected to support one-click unsubscribe. Klaviyo adds the header for you, but only if your template keeps the unsubscribe link.
- Do not buy or borrow lists. One purchased list can undo a year of reputation work.
Step 4: Clean the list before it cleans you
Sending to people who never open teaches inboxes that your mail is unwanted. Build a sunset policy: after a set number of sends with no engagement, move a contact into a short re-engagement series, then stop emailing them if they stay silent. We explain why this protects revenue in how a sunset flow protects sender reputation.
Also confirm your signup forms use clear consent and, where it helps, a confirmation step. Fewer bad addresses at the door means fewer bounces later.
Step 5: Warm up changes carefully
A new domain, a new sending volume, or a long gap in sending all change how inboxes see you. Ramp up gradually, starting with your most engaged contacts. Do not send a full-list blast the day a new domain goes live.
How to know you have a problem
- Open rates fall across every flow and campaign at the same time
- Revenue per recipient drops while list size grows
- Bounce or spam complaint rates rise
- Flows that used to convert, like welcome and abandoned cart, go quiet
These signs look like a content problem. They are usually an infrastructure problem. We lay out what fixing it first is worth in the real ROI of fixing deliverability first.
Check yours in ten seconds
Run the free scan. It reads your domain’s public SPF, DKIM and DMARC settings and gives you a grade from A to F, plus a plain-English fix list. No login and no access to your Klaviyo account needed.
If you would rather have it fixed than read about it, see our Klaviyo deliverability fix.
Related reading: our email deliverability and DMARC tools guide and the longer explainer on what breaks deliverability and how to fix it.
