Set up a custom email domain

Customers are able to specify custom subdomains without the need to use smartsheetmail or smartsheet.customdomain.com, e.g. customsubdomain.customdomain.com. Customers can still specify smartsheet or smartsheetmail if they want.

The subdomain must not have a TXT record associated with it and must use a primary domain that does have a validated TXT record. DNS rules prevent a subdomain (or any domain name) from having both a CNAME and a TXT record.

Custom email domains work for any user triggered emails from the Smartsheet app, including:

• Automated alerts
• Update request
• Share sheet
• @mention

Custom email domains are not supported for Smartsheet welcome emails and system emails, such as password reset or payment notification emails.

Any subdomain used to send emails requires a CNAME record to be implemented, which blocks that subdomain from sending emails. As a result, the sending subdomain should not have an email inbox associated with it. 

Before you begin

You must be able to update public DNS (Domain Name System) records of your primary domain and custom email domain, or work with your IT team or domain administrator. If your organization has multiple Smartsheet accounts, those accounts must be configured separately. They can share the same custom email domain.

The sending domain must be a subdomain of your primary domain. You need to validate that you are the owner of the primary domain through Admin Center’s domain validation flow. For more information, see Automatically add users with User Auto Provisioning (UAP).

Public DNS entries required for the setup

To enable sending email on behalf of your organization using your custom email domain, the following public DNS settings are required to grant permission to SparkPost (the Smartsheet app’s email service provider), so that we satisfy SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail) and DMARC (Domain-Based Message Authentication, Reporting and Conformance) email security standards.

You may need to work with your IT team to set up the required public DNS entries.

• Domain key (DKIM) record: All the Smartsheet emails sent with the custom domain have an encrypted digital signature in the mail header. The receiving mail server validates the email message by looking up the custom domain’s DKIM key and uses it to verify the encrypted signature. This email authentication mechanism protects the senders and recipients from spoofing and phishing by verifying the emails are sent from the legitimate sender.
• CNAME record: This points the custom email domain to the SparkPost domain, which contains an SPF record for another authentication mechanism that protects senders and recipients from spoofing and phishing. The SPF record defines which mail servers are authorized to send mail from the custom domain. The receiving mail server looks these up from the SPF record and compares the IP address of the mail sender to verify that the email is sent from the authorized sender mail server.
  • Any subdomain used to send emails requires a CNAME record to be implemented, which blocks that subdomain from receiving emails. As a result, the sending subdomain should not have email inboxes associated with it.
  • Subdomains should not have a TXT record, as the primary domain is required to have a TXT record and go through domain validation. 
• DMARC record: This defines the actions to be taken by the receiving mail server when emails claim to be from the custom email domain but fail DKIM and/or SPF authentication. We recommend setting the policy to quarantine or reject the emails to prevent unauthenticated parties from spoofing mail from the domain.

Configure your account to use a custom email domain

As a System Admin, you can visit the Branding and Personalization settings page in Admin Center to configure a custom email domain for your organization.

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The setup wizard walks you through the following steps:

1. Ensure your account has a validated primary domain. If not, you are taken to the Domain Validation page to add and validate your primary domain.
2. Add the subdomain to the domain validation page. It does not need to be validated; however, this allows it to be displayed in the custom subdomain dropdown menu. 
3. Select the custom email domain name to be used for the setup.
4. The setup wizard presents the public DNS records you need to create for your custom email domain. If you don't have access to modify your organization’s public DNS, you should take the information to your IT team or domain administrators to set those up.
5. After the public DNS records are created for the custom email domain, you need to complete the verification step in Admin Center.
6. When verification of the custom domain is completed successfully, the feature is enabled for your organization. All users of your organization will start seeing Smartsheet emails sent from your custom email domain.
   There is a warm-up period of 10 days when emails are gradually switched from smartsheet.com to the new sending domain.

Users in the organization don't need to do anything differently when creating notifications, such as sharing, send sheet, and automated workflows. Once the custom email domain public DNS setup is completed, the feature is enabled, and existing notifications and new ones will start using the custom email domain in the sender address.

After public DNS records are created, the changes may take up to 72 hours to propagate across the internet. During this time, the public DNS verification from the setup wizard would fail, and you should check that you have set up the public DNS correctly and wait to try again.