Understand the domains that play a role in email deliverability

You will learn

Learn about the different domains that play a role in the delivery of your emails, as well as the importance of domain alignment.

From Address domain

The From Address domain, also known as the “friendly from address domain,” refers to the domain associated with the email address that you are sending from.

This is the most important domain in your emails because your subscribers see it in their inbox. It represents your brand and is the primary domain that email providers use to track your reputation.

In a typical inbox, like Gmail, the From Address is displayed in the sender information section.

You can set the From Address and the accompanying "From" name for any campaign in Klaviyo.

Sending domain

A sending domain is the domain used to send emails, and shows subscribers where your emails are sent from. By default, most accounts begin with sending from a shared Klaviyo domain. This domain appears in the sender information at the top of an email message. For example, in Gmail, your recipients see "via klaviyomail.com" because you are using a shared sending domain.

A branded sending domain allows you to send emails that appear to be coming from your brand instead of Klaviyo, giving you better control of your sender reputation. Moving to a branded sending domain removes the "via klaviyomail.com" message displayed beside your sender email address when your From Address domain aligns with it.

Inbox providers such as Google and Yahoo enforce sender requirements for bulk senders, and setting up a branded sending domain is part of meeting those requirements. As a reference point, Google’s bulk-sender requirements apply when you send 5,000 or more emails to personal Gmail accounts per day. All traffic counts toward this threshold, including transactional emails.

When you add a branded sending domain, you choose an Email type that determines the kind of traffic it carries:

• Marketing: campaigns and promotional flows
• Transactional: flow messages designated as transactional (for example, order confirmations and password resets)
• Service: support emails sent through Klaviyo Helpdesk, including replies sent by Customer Agent. Enable inbound email in your email settings before selecting Service.

You can configure separate branded sending domains for each email type in the same account, so each kind of traffic builds its own sender reputation. For details, see How to set up a branded sending domain.

Return-Path domain

A Return-Path domain (also known as Mail From, Envelope From, origin, bounce address, SPF domain, mailed-by, or mail server domain) is the domain in the address used to receive bounce notifications.

This domain is necessary for the delivery of your message, but it's usually hidden from the recipient. For example, Gmail shows it in a hidden dropdown as the “mailed-by” domain. You can see this by clicking to me in your Gmail message.

With Klaviyo, the Return-Path domain depends on your sending setup. It can use a shared Klaviyo domain, such as klaviyomail.com, your branded sending domain, or one of its subdomains. Klaviyo manages bounce handling for this domain. If a message bounces, Klaviyo automatically logs the event in your account.

When an inbox provider like Gmail receives a message, it checks the Return-Path domain for the SPF record. Klaviyo manages SPF for its shared sending domains. For a branded sending domain, complete the DNS setup provided by Klaviyo. The CNAME or NS records enable SPF authentication. You do not need to add Klaviyo to your root domain’s SPF record.

DKIM domain

A DKIM domain (also known as the “signed-by domain” or d= domain) identifies the domain used to digitally sign your emails. The receiving mailbox provider checks the signature to verify that the message was authorized by that domain. The DKIM domain can differ from the From Address or Return-Path domain, but it must align with the From Address domain for DKIM to satisfy DMARC.

By default, the DKIM domain is one owned and operated by Klaviyo, such as klaviyomail.com. This allows DKIM to work immediately when you start with Klaviyo.

In Gmail, the DKIM domain appears as the “signed-by” domain in the message details. Gmail may also show “via” information when the sending domain differs from the From Address domain.

When you set up a branded sending domain, your email is DKIM-signed by your own domain in addition to a shared Klaviyo domain.

Click tracking domain

Click-tracking domains are used to track clicks on the links you include in your content. When someone clicks a link, they are redirected through a URL associated with the click-tracking domain and then immediately passed through to the original URL.

If you hover over a link in your inbox you can see the full tracking link.

A dedicated click-tracking domain displays your own domain on click-tracking links rather than Klaviyo's default. Having recognizable links in the emails coming from your brand helps build trust with the customers receiving those emails. Instead of a long string of letters and numbers from a trk.klaviyomail encoded link, they see your brand's name when hovering over links in your email. This familiarity may increase the chances they click on your links.

Many mailbox providers and filtering software also consider the reputation of all domains used in your messaging. Using the same root domain in both your dedicated click-tracking domain and your sending domain creates alignment across your brand identity.

You need a paid Klaviyo account to configure a dedicated click-tracking domain. For setup, verification, and activation instructions, see How to set up dedicated click tracking.

Domain alignment for DMARC

DMARC passes when SPF or DKIM authentication passes and that authenticated domain aligns with your From Address domain. In Klaviyo, set up a branded sending domain that shares the same root domain as your From Address. For example, if you send an email using sales@example.com as the From Address and example.com is protected by DMARC, a branded sending domain like send.example.com aligns under DMARC’s relaxed alignment mode. If your DMARC policy uses strict alignment, the authenticated SPF or DKIM domain must exactly match your From Address domain.

Bulk senders must publish a DMARC record to meet inbox provider requirements. A policy of p=none meets the initial DMARC requirement. Work with your IT team or a third-party DMARC service provider to choose and implement a policy that fits your brand’s sending across all services.

You can align the DKIM domain with your From Address by setting up a branded sending domain.

Benefits of domain alignment

There are 2 major benefits of domain alignment:

1. Domain alignment allows DMARC to pass when SPF or DKIM authentication also passes. In Klaviyo, an aligned branded sending domain lets you meet this requirement through DKIM.
2. Aligning as many domains as possible helps establish your domain reputation. Inbox providers and spam filters often consider domain alignment when deciding if you are reputable. Recipients are more likely to trust you as a sender if your domains align (for example, From Address domain matching the click-tracking domain).

It is best practice to align your sending domain, DKIM domain, click-tracking domain, and From Address domain where possible. This supports a consistent brand identity and sender reputation, but does not guarantee inbox placement.

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