Authenticating a Sending Domain

Implementing domain authentication to a Sending Domain is a way to verify that an email came from the sender listed in the “from” field in the recipient’s inbox, and that the email was not forged or tampered with while in transit. Implementing domain authentication is an email industry best practice and considered a “must do” to secure a strong sending reputation.

Before Getting Started

Successfully setting up a Sending Domain is an impactful change to your email marketing strategy. All Professional Plus users, particularly those with 100k Contacts or more, should strongly consider taking advantage of the whiteglove support provided by Sendlane's Customer Success Managers to complete this process!

Setting up a Sending Domain with Sendlane requires you to add information to your DNS host. This may require the involvement of your business' IT department.

In This Guide

What is Domain Authentication?

Domain Authentication is a way to let mailbox providers (Google, Yahoo, Microsoft, etc.) know that the emails sent from your Sending Domain belong to you. It provides confidence to the receiver that the email they received from you was not forged during transit. The most common standards used for authentication are SPF, DKIM, and DMARC. These are technical solutions to prove the email was not imitated.

What is a Sending Domain?

A Sending Domain is the domain that identifies from whom an email campaign is sent. It is the domain in the “from” address in an email. A domain name should reflect your company name. This is an important factor in building trust with recipients and increasing response rates from recipients.

In the example below, the Sending Domain is This Sending Domain clearly identifies the sender as Microsoft.

Creating a Subdomain and NS Records

Complete the following two steps in your host server account:

  1. Create a Subdomain: Create a subdomain of your main Sending Domain to encourage brand recognition. For example, if your domain is “,” an appropriate subdomain would be “”
  2. Add Nameserver (NS) Records: The following NS records must be added in the intended subdomain (Sendlane’s default TTL is 3600 seconds):

Setting Up Sending Domains in Sendlane

Navigate to AccountSending DomainsSetup Domain

Enter your Domain Name ( and Sending Domain (“mail” for → click Save

After clicking Save, the Sending Domain Authentication pop-up window will populate with the Sending Domain you’ve just created and the following information:

  • Host - The customer’s desired Sending Domain
  • Value - In most DNS settings interfaces this field is labeled “Points To”
  • TTL - Some domain providers describe TTL in hours or minutes rather than seconds, Sendlane’s default TTL of 3600 seconds equals 1 hour or 60 minutes

Exit the pop-up window and click the Re-Verify DNS icon to communicate with your DNS. You may not see an immediate change because DNS records can take up to 24 hours to successfully update.

Attaching Sender Profiles to Sending Domains

Sending Domains must be linked to at least one new or existing Sender Profile.

Once your NS Set and DNS Verified icons are populated with green checkmarks, click the link icon button in the Actions column of the Sending Domain page to open the Connect to Sender window:

In the Connect to Sender window:

  1. Select a Sender Type
    1. New - All fields are required to save a new Sender Profile
    2. Existing - Select an existing Sender Profile and edit any field as needed
  2. Fill out or edit the Sender fields as needed
    1. From Email fields cannot be edited from this window in an existing Sender Profile.
    2. Reply To email addresses can be different from the From Email and should be an active email address using the customers’ main domain (not a free email address like Gmail) if they want to receive replies from their contacts.
    3. The Sender’s address must be a valid physical mailing address or P.O. Box.
  3. Click Confirm

The Sender Profile that was created or attached to the new Sending Domain will appear first on the Sender Profile tab of the Audience page, and will be identified by a green checkmark next to the Sender Name

Add additional Sender Profiles to the same domain by clicking the link icon


I added my subdomain and NS records, but they are not authenticated in Sendlane!

If you use separate services for your domain and hosting please make sure you've added the subdomain and associated NS records in your hosting account.

I use Amazon Web Services for domain hosting and can only add one NS record!

Create one NS record for the subdomain you are delegating to Sendlane and enter the four required values on one line each in the Value field of the Create Record console

I use Google Domains and can't add NS records!

Check out Google's instructions under "Create or modify a resource record," then make sure to add the four NS records in a single row

I need my Sending Domain Type, Host, Value, or TTS information!

This information can be retrieved by clicking the pink arrow next to the Root Domain on the Authenticated Sending Domain page:

Need further assistance? Our 24/7 support team is just a click away!

Did this answer your question? Thanks for your feedback! There was a problem submitting your feedback. Please try again!

Still need help? Get in touch! Get in touch!