Every email travels the same route
The journey of an email isn’t that different from the journey of a letter. Both start with the sender, and both pass through a series of checks designed to stop harmful content before it reaches the recipient. Watch the video below to follow a message from the moment you hit send to the moment it lands.
Work through the six stages below to review the route. Use the controls to move forward and back through each stage at your own pace.
This is the stamp-on-the-envelope stage. Before a message can begin its journey, it needs a few key components:
- A subject line
- Sender information
- Your company’s physical address
- An unsubscribe link
Think of Klaviyo as your local mail carrier. Your ESP runs initial spam filters to confirm the content isn’t intended to harm your recipient, then passes the message along for delivery.
Inbox providers like Gmail and Outlook collect mail on behalf of recipients. At this stage every component of your email is inspected and flagged if it looks malicious, including your written content, links, branding, HTML code, and email size.
They also check everything used to authenticate your identity, such as your sending domain, IP address, and DMARC policy. On top of that, they can see whether your emails are opened, filtered, or deleted without being read, and they track how engaged your audience is over time.
Your message may also be screened by additional filters such as Cloudmark, or checked against block lists such as Spamhaus. Once these checks clear, the message is routed onward.
Where the message lands depends on everything that came before it:
- The inbox. For providers like Gmail that use a tabbed inbox, marketing messages often land in the Promotions tab. That is normal and nothing to worry about.
- The spam folder. If the provider finds malicious or spam-related content, your message is quarantined here.
- Nowhere at all. When a message cannot be delivered, that is a bounce.
Landing in the inbox isn’t the finish line. How recipients interact with that email, whether they open it and click into the content, shapes how those same inbox providers judge your next send.
That feedback loop is the heart of why deliverability matters. Monitor each send’s performance in Klaviyo, because the moment you hit send again, the cycle begins from stage one.