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This guide walks you through adding the required DNS records for Lettr using AWS Route 53. Route 53 is Amazon Web Services’ scalable Domain Name System (DNS) web service, managed through the AWS Management Console. Route 53 organizes DNS records into hosted zones, where each hosted zone corresponds to a domain. You will configure a sending domain (CNAME, DKIM TXT, and DMARC TXT records) and, optionally, an inbound domain (MX records), tracking domain (two CNAME records), and storage domain (CNAME and two TXT records).

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Sending Domain Setup

A sending domain authenticates your outgoing emails with DKIM and DMARC, ensuring they are delivered reliably and not marked as spam. This requires a CNAME record for domain verification, a TXT record for DKIM signing, and a TXT record for DMARC policy. To create a sending domain in Lettr:
  1. Select Domains in the navigation panel
  2. Select Sending Domains
  3. Click Create Sending Domain
  4. Enter your desired sending subdomain (e.g. mailing.company.com)
  5. Click Create Domain
Use a subdomain (e.g. mailing.company.com) instead of the root domain (company.com). A subdomain provides proper reputation segmentation and is required if you also plan to receive emails with Lettr.
Click your new domain in the Sending Domains list. This will display a list of DNS records that need to be configured. Keep this page open — you will need these values soon.

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Configure Route 53 DNS

Log in to the AWS Route 53 Dashboard. In the left sidebar, click Hosted zones and select the Hosted zone (domain) you want to configure, or create a new one. Hosted zones list in AWS Route 53 dashboard This will open the Hosted zone details page, where you can manage your DNS records. Hosted zone details page in AWS Route 53
If your domain was purchased through AWS Route 53 or your nameservers already point to AWS Route 53, skip nameserver configuration entirely. Your domain is already using AWS Route 53’s nameservers by default — proceed directly to adding the DNS records below.
If you registered your domain elsewhere but want to manage DNS on AWS Route 53, you must first update the nameservers at your registrar to AWS Route 53’s nameservers shown in the domain configuration.AWS Route 53 nameserver configuration
Until the nameservers are updated, any records you add in AWS Route 53 will not resolve.

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Add CNAME Record

The CNAME record verifies domain ownership with Lettr’s email infrastructure. Copy the CNAME values from Lettr to Route 53:
  1. Click Create record in your Hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select CNAME from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53.
  5. Leave TTL set to 300 (Route 53 default).
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of mailing.lettr-demo.com, paste only mailing. Route 53 displays the hosted zone domain as a greyed-out suffix next to the Record name field.
Adding CNAME record in AWS Route 53

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Add TXT Record (DKIM)

The DKIM record adds a cryptographic signature to your outgoing emails, allowing recipients to verify they were sent by an authorized sender. Copy the TXT values from Lettr to Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select TXT from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53. Enclose the value in double quotes (e.g. "v=DKIM1; ...").
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Route 53 requires TXT record values to be enclosed in double quotes. If you paste the value without quotes, the record will fail to save or will be stored incorrectly.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of scph0126._domainkey.mailing.lettr-demo.com, paste only scph0126._domainkey.mailing.
Adding DKIM TXT record in AWS Route 53

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Add TXT Record (DMARC)

The DMARC record tells receiving mail servers how to handle emails that fail authentication checks, protecting your domain from spoofing. Copy the TXT values from Lettr to Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select TXT from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53. Enclose the value in double quotes.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of _dmarc.mailing.lettr-demo.com, paste only _dmarc.mailing.
Adding DMARC TXT record in AWS Route 53

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Verify Your Sending Domain

After adding all three DNS records, go back to Lettr and click Verify DNS Records. DNS propagation can take up to 24–48 hours, though it typically completes within a few minutes.

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Inbound Domain Setup

An inbound domain allows Lettr to receive emails on your behalf. This requires three MX records that direct incoming mail to Lettr’s mail servers.

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Add Inbound Domain to Lettr

To create an Inbound domain in Lettr:
  1. Select Domains in the navigation panel
  2. Select Inbound Domains
  3. Click Create Inbound Domain
  4. Enter your desired inbound subdomain (e.g. inbound.company.com)
  5. Click Create Domain
Click on your new domain in the Inbound Domains list. This will display the MX records that need to be configured. Keep this page open — you will need these values in the next steps.

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Add MX Records

MX records tell other mail servers where to deliver emails addressed to your domain. Copy the MX values from Lettr to Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select MX from the Record type dropdown.
  4. In the Value field, enter all three MX records, each on a separate line, in the format priority mailserver. For example: 
    10 rx1.sparkpostmail.com
10 rx2.sparkpostmail.com
10 rx3.sparkpostmail.com
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Route 53 combines all MX records for the same name into a single record set. Enter each MX record on a separate line within the same Value field, with the priority number before the mail server address.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of inbound.lettr-demo.com, paste only inbound.
Adding MX records in AWS Route 53

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Verify Your Inbound Domain

After adding the MX records, go back to Lettr and click Verify DNS Records. DNS propagation can take up to 24–48 hours, though it typically completes within a few minutes.

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Tracking Domain Setup

A tracking domain allows Lettr to track email opens and link clicks using your own custom domain instead of the default Lettr tracking domain. This requires two CNAME records: one for the SSL certificate and one for routing tracking traffic to Lettr’s infrastructure.

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Add Tracking Domain to Lettr

In the Lettr dashboard, select Domains in the navigation panel, then select Tracking Domains and click Create Tracking Domain. Enter your desired tracking subdomain (e.g. track.company.com) and click Create Tracking Domain. Click on the name of your new tracking domain in the Tracking Domains list. This will display the CNAME records that need to be configured. Keep this page open — you will need these values in the next steps.

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Add SSL Certificate CNAME Record

The SSL Certificate CNAME record provisions an SSL certificate for your custom tracking domain, enabling secure HTTPS connections for tracked links. Add the record in Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select CNAME from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of track.lettr-demo.com, paste only track.
Adding SSL Certificate CNAME record in AWS Route 53

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Add Traffic CNAME Record

The Traffic CNAME record routes click and open tracking requests from your custom domain to Lettr’s tracking servers. Add the record in Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select CNAME from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of track.lettr-demo.com, paste only track.
Adding Traffic CNAME record in AWS Route 53

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Verify Your Tracking Domain

After adding both CNAME records, go back to Lettr and click Verify DNS Records.

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Storage Domain Setup

A storage domain lets you serve email assets (images, attachments) from your own custom domain instead of the default Lettr storage URL. This requires two TXT records for certificate validation and ownership verification, and a CNAME record for routing asset requests to Lettr’s storage infrastructure.

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Add Storage Domain to Lettr

In the Lettr dashboard, select Domains in the navigation panel, then select Storage Domains and click Create Storage Domain. Enter your desired storage subdomain (e.g. assets.company.com) and click Create Storage Domain. Click on your new domain in the Storage Domains list. This will display the TXT and CNAME records that need to be configured. Keep this page open — you will need these values in the next steps.

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Add TXT Record (Certificate Validation)

The Certificate Validation TXT record provisions an SSL certificate for your custom storage domain, enabling secure HTTPS delivery of email assets. Add the record in Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select TXT from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53. Enclose the value in double quotes.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of assets.lettr-demo.com, paste only assets.
Adding Certificate Validation TXT record in AWS Route 53

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Add TXT Record (Hostname Pre-validation)

The Hostname Pre-validation TXT record verifies ownership of the storage domain before Lettr provisions a custom hostname for it. Add the record in Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select TXT from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53. Enclose the value in double quotes.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
If the Record name is the same as the Certificate Validation TXT record above, Route 53 will not allow two separate TXT record sets with the same name. Instead, edit the existing TXT record and add the new value on a separate line, with each value enclosed in its own double quotes.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of assets.lettr-demo.com, paste only assets.
Adding Hostname Pre-validation TXT record in AWS Route 53

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Add CNAME Record (Domain Routing)

The Domain Routing CNAME record routes asset requests from your custom domain to Lettr’s storage infrastructure. Add the record in Route 53:
  1. Click Create record in your hosted zone.
  2. Copy the Hostname from Lettr and paste it into the Record name field in Route 53.
  3. Select CNAME from the Record type dropdown.
  4. Copy the Value from Lettr and paste it into the Value field in Route 53.
  5. Leave TTL set to 300 or adjust as needed.
  6. Ensure Routing policy is set to Simple routing.
  7. Click Create records.
Omit your domain suffix from the Hostname when pasting into Route 53. For example, instead of assets.lettr-demo.com, paste only assets.
Adding Domain Routing CNAME record in AWS Route 53

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Verify Your Storage Domain

After adding all three records, go back to Lettr and click Verify DNS Records.

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Troubleshooting

Route 53 requires all TXT record values to be enclosed in double quotes. If you paste a value without quotes, the record may fail to save or resolve incorrectly. Edit the record and ensure the value is wrapped like "v=DKIM1; ...".
Route 53 does not allow two separate record sets of the same type with the same name. If you need to add multiple TXT values for the same hostname (e.g. both storage TXT records share a name), add them as separate lines within a single TXT record set, each enclosed in its own double quotes:
"certificate-validation-value-here"
"hostname-prevalidation-value-here"
Route 53 displays the hosted zone domain as a greyed-out suffix next to the Record name field. If you paste the full hostname (e.g. mailing.lettr-demo.com), the resulting record will be mailing.lettr-demo.com.lettr-demo.com, which will fail verification.Always paste only the subdomain portion (e.g. mailing, scph0126._domainkey.mailing, _dmarc.mailing).
If verification fails after adding records, check the following:
  • Wait at least 30 minutes before your first verification attempt. Most records propagate within 1–2 hours.
  • Confirm the records exist using command-line tools:
# Check CNAME record
dig CNAME mailing.yourdomain.com +short

# Check DKIM record
dig TXT scph0126._domainkey.mailing.yourdomain.com +short

# Check DMARC record
dig TXT _dmarc.mailing.yourdomain.com +short

# Check MX records (inbound)
dig MX inbound.yourdomain.com +short

# Check tracking domain CNAME
dig CNAME track.yourdomain.com +short

# Check storage domain CNAME
dig CNAME assets.yourdomain.com +short
  • Use a web tool like dnschecker.org to verify propagation across multiple DNS servers worldwide.
A common mistake is selecting the wrong type in Route 53’s Record type dropdown:
RecordCorrect Type
Sending verificationCNAME
DKIMTXT
DMARCTXT
Inbound mailMX
Tracking SSL certificateCNAME
Tracking trafficCNAME
Storage certificate validationTXT
Storage hostname pre-validationTXT
Storage domain routingCNAME
The DKIM TXT value is a long string. After saving the record in Route 53, click the record to confirm the full value was stored. If it appears truncated, edit the record and try pasting the value again. Remember to enclose the entire value in double quotes.
Route 53 does not support CNAME records at the zone apex (root domain). For example, you cannot create a CNAME record for company.com itself — only for subdomains like mailing.company.com. Use a subdomain for your sending domain to avoid this limitation.
If you need to use the root domain, consider using Route 53’s Alias record type, which works at the zone apex. However, Alias records only support routing to specific AWS resources and may not work for Lettr’s CNAME targets. Using a subdomain is the recommended approach.
If your records are saved in Route 53 but not resolving, confirm that your domain registrar is pointing to Route 53’s nameservers. You can check this with:
dig NS yourdomain.com +short
The output should include the four nameservers listed in your Route 53 hosted zone (e.g. ns-123.awsdns-45.com, ns-456.awsdns-67.net). If it shows a different provider’s nameservers, update them at your domain registrar.
If your DNS records are correctly configured (confirmed with dig or dnschecker.org) and verification still fails after 48 hours, contact Lettr support at support@lettr.com or through the in-app chat. Include your domain name and the output of the dig commands above.

Sending Domains

Learn about sending domain setup, SPF, DKIM, and DMARC.

Inbound Domains

Configure MX records to receive emails with Lettr.

Tracking Domains

Set up a custom tracking domain for click and open tracking.

Storage Domains

Serve email assets from your own custom domain.

Domains Overview

Understand domain types and how they work in Lettr.

Domain Verification Failures

Troubleshoot common DNS configuration and propagation issues.