Email Branding

Where this applies

Email branding affects the three transactional emails Koolbase sends on your behalf:

• Verification emails sent at signup
• Password reset emails sent when users request a reset
• "No account" courtesy emails sent when a reset is requested for an unregistered address — a UX nicety that lets the user know they probably signed up with a different email

Visual branding settings live under Branding in your project sidebar. Custom domains live under Sender Domains.

Display name

The display name is the brand identifier shown throughout the email body — subject lines, headers (when no logo is set), and footer copyright. It also flows through to other settings as a fallback when they're blank.

Falls back to: your project name. If your project is called "StrideHx Inc" and you don't set a display name, all emails read "StrideHx Inc" by default.

From name

The display name in the From: header of the email — what recipients see in their inbox preview alongside the actual sender address (e.g., StrideHx Inc <auth@koolbase.com>).

Falls back to: the display name, then the project name. Most projects set this once and forget it.

Reply-to email

Where replies to transactional emails should route. When set, Koolbase adds a Reply-To: header so any reply from the recipient goes directly to your address instead of bouncing off the shared Koolbase sender.

Leave blank if you don't want recipients to reply at all — the Reply-To header simply won't be set.

Logo

Logo image rendered at the top of every transactional email, replacing the text display name in the header. When no logo is uploaded, the display name renders as bold white text.

• Format: PNG or JPEG only. SVGs aren't supported — mail clients render them inconsistently.
• Size limit: 1 MB.
• Rendered height: 40px, scaled proportionally.

Primary color

Accent color used as the background of primary buttons in transactional emails — specifically the "Verify Email" and "Reset Password" buttons. Six-digit hex format (e.g., #E63946).

Falls back to: Koolbase blue (#2b8cee) when blank.

Sender domains

By default, Koolbase's transactional emails send from the shared auth@koolbase.com address. To send from your own domain (e.g., noreply@yourdomain.com), register and verify a custom sender domain.

Each project can register multiple domains and switch between them, but only one is the active sender at a time.

1. Add your domain

From the Sender Domains tab in your project sidebar, click Add domain and enter the root domain or subdomain you want to send from. Koolbase registers it with our delivery provider and returns the DNS records you need to publish.

curl -X POST https://api.koolbase.com/v1/projects/{project_id}/domains \
  -H "Authorization: Bearer YOUR_DASHBOARD_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "domain": "yourdomain.com" }'

2. Publish the DNS records

The response includes a list of DNS records — typically one MX (SPF), one TXT (SPF), and two or three CNAME (DKIM) records. Add each one at your DNS provider. Each card in the Sender Domains tab has copy buttons so you can paste the values directly.

[
  {
    "type": "MX",
    "name": "send",
    "value": "feedback-smtp.us-east-1.amazonses.com",
    "priority": 10,
    "ttl": "Auto"
  },
  {
    "type": "TXT",
    "name": "send",
    "value": "\"v=spf1 include:amazonses.com ~all\""
  },
  {
    "type": "CNAME",
    "name": "{selector}._domainkey",
    "value": "{selector}.dkim.amazonses.com."
  }
]

3. Verify

After publishing your records, click Verify on the domain card. Koolbase triggers a DNS check on our delivery provider; the status updates from pending to verified once the records resolve correctly.

4. Activate

Once verified, click Activate on the domain card. From that moment, all transactional emails for this project send from noreply@yourdomain.com instead of auth@koolbase.com. Click Deactivate any time to switch back to the shared sender without removing the registration.

Fallback chain

Koolbase applies fallback logic so emails always have sensible defaults, even when branding is partially configured:

API reference

Most projects configure branding from the dashboard, but every setting is also reachable via the API for automation or CI workflows.