assets.yourcompany.com. This keeps your email source code looking professional, improves deliverability by using your own trusted domain, and ensures recipients see your brand in image URLs when inspecting your emails.
Why Use Storage Domains?
When you use Lettr’s email editor or upload images, they’re hosted on Lettr’s storage. By default, these assets are served from Lettr’s domain:Benefits
- Brand Consistency - Image URLs show your domain in email source
- Improved Deliverability - Links to your domain may be trusted more than third-party hosts
- Professional Appearance - Clean, branded URLs for all email content
- Link Inspection - Recipients can see URLs point to your domain before clicking
What Storage Domains Host
Storage domains serve content from Lettr’s cloud storage:| Content Type | Description |
|---|---|
| Template Images | Images uploaded to email templates |
| Email Assets | Files attached to email content |
| Hosted Emails | Web-hosted versions of sent emails |
| Template Previews | Preview images for templates |
Adding a Storage Domain
Via Dashboard
Add DNS Records
Add the provided DNS records to your domain:
- A CNAME record pointing to Lettr’s storage
- TXT records for domain ownership verification
Storage domains are managed through the Lettr dashboard. API endpoints for storage domains are not currently available.
DNS Configuration
Configure these DNS records for your storage domain:CNAME Record
Points your subdomain to Lettr’s storage servers:| Field | Value |
|---|---|
| Type | CNAME |
| Name | assets (your chosen subdomain) |
| Value | r2-proxy.uselettr.com |
SSL Validation TXT Record
Required for SSL certificate provisioning:| Field | Value |
|---|---|
| Type | TXT |
| Name | _cf-custom-hostname.assets |
| Value | (provided by Lettr) |
Ownership TXT Record (if required)
Additional ownership verification (may be required by Cloudflare):| Field | Value |
|---|---|
| Type | TXT |
| Name | (provided by Lettr) |
| Value | (provided by Lettr) |
TXT record values are unique to your domain. Copy them exactly as provided in your dashboard.
Choosing a Subdomain
Common choices for storage subdomains:| Subdomain | Full Domain | Use Case |
|---|---|---|
assets | assets.example.com | General email assets |
images | images.example.com | Image-focused |
cdn | cdn.example.com | CDN-style naming |
email | email.example.com | Email-specific content |
content | content.example.com | All email content |
SSL Certificates
Lettr automatically provisions SSL certificates for your storage domain. All content is served over HTTPS.SSL Status
| Status | Description |
|---|---|
active | SSL certificate active, domain ready to use |
pending | Certificate being provisioned |
pending_validation | Waiting for TXT record validation |
initializing | Initial setup in progress |
Verifying Your Storage Domain
Via Dashboard
- Go to Domains → Storage
- Find your domain and click Verify
- Wait for CNAME and SSL verification to complete
Storage Domain Status
| Status | Description |
|---|---|
active | Domain verified and serving content |
pending | Awaiting DNS verification |
not_found | Domain configuration not found |
Setting a Default Storage Domain
If you have multiple storage domains, set one as the default for new uploads:Via Dashboard
- Go to Domains → Storage
- Find the domain and click Set as Default
Domain Limits
Each team can configure up to 5 storage domains. This allows for:- Different domains for different brands
- Separate domains for different email types
- Testing domains alongside production
Contact support if you need more than 5 storage domains.
Using Storage Domains
Once configured, your storage domain is used automatically:Template Images
When you upload images in the email editor, they’re hosted on your storage domain:Hosted Emails
Web versions of sent emails are accessible via your storage domain:Updating Existing Templates
When you verify a storage domain, existing templates can be updated to use the new domain. This happens automatically for the default storage domain.Delete a Storage Domain
Via Dashboard
- Go to Domains → Storage
- Find the domain and click Delete
- Confirm deletion
Troubleshooting
CNAME not verified
CNAME not verified
- Verify the CNAME record points to
r2-proxy.uselettr.com - Check the record is added to the correct subdomain
- DNS propagation can take up to 48 hours
- Use a DNS lookup tool to verify your CNAME is resolving
SSL certificate pending
SSL certificate pending
- Ensure TXT records are added exactly as provided
- TXT records must be on the correct subdomain
- Certificate provisioning can take up to 24 hours in rare cases
Images not loading
Images not loading
- Verify domain status is
active - Check that SSL status is
active - Ensure the image path is correct
- Try clearing browser cache
Domain limit reached
Domain limit reached
- Each team is limited to 5 storage domains
- Remove unused domains to add new ones
- Contact support for increased limits
Existing templates using old domain
Existing templates using old domain
- Templates created before adding a storage domain use Lettr’s default
- Re-save templates to update image URLs
- Or manually update image URLs in template HTML
Best Practices
- Use a dedicated subdomain - Don’t use your root domain for storage
- Set up early - Configure storage domains before creating templates
- Use consistent naming - Pick one subdomain naming convention across your domains
- Set a default - Always have a default storage domain configured
- Monitor SSL - Ensure certificates remain active