> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sinosend.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Create a Branded File Portal with Your Custom Domain
> Deliver files under your own brand with custom domains, white-label emails, and a fully tailored download experience. Business plan required.
When your clients or suppliers open a file you sent, what they see reflects on your business. Sinosend's Branded Portals replace every Sinosend touch-point — the download page, the delivery email, the notification sender address — with your company's own identity. Recipients experience a polished, professional file delivery service that belongs entirely to you.
Branded Portals require a **Business plan**. Custom domain setup, white-label email sending, and custom CSS are not available on Free or Pro plans.
## What a branded portal is
A branded portal is your own file delivery experience, hosted by Sinosend but presented entirely under your brand. It consists of:
* A **custom domain** (e.g., `files.yourcompany.com`) that hosts your download pages.
* **White-label email delivery** — notification and delivery emails arrive from your domain, not from `@sinosend.com`.
* A **customised download page** with your logo, background, colours, and optional custom CSS.
* **No Sinosend branding** anywhere visible to recipients.
## Set up a custom domain
In your dashboard, click **Settings** in the left sidebar, then select **Branded Portal**.
Type the subdomain you want to use — for example, `files.yourcompany.com` or `docs.yourcompany.com`. Sinosend recommends using a subdomain of your main domain rather than a root domain.
Choose a subdomain that signals file delivery to recipients — `files.`, `docs.`, `share.`, or `send.` work well. Avoid subdomains already used by other services (such as `www.` or `mail.`).
Sinosend displays the CNAME target you need to add to your DNS provider. Log in to your domain registrar or DNS management console (e.g., Cloudflare, Route 53, GoDaddy) and create a CNAME record:
| Type | Name | Value |
| ----- | --------------------- | --------------------- |
| CNAME | `files` (your prefix) | `portal.sinosend.com` |
DNS propagation typically takes between 5 minutes and 48 hours depending on your provider.
Return to the Sinosend Branded Portal settings and click **Verify Domain**. Sinosend checks for the CNAME record and, once confirmed, activates your portal and provisions an SSL certificate automatically.
## SSL certificate
Sinosend automatically provisions and renews a free SSL certificate for your custom domain via Let's Encrypt. Your portal is always served over HTTPS — no manual certificate management required.
Do not add your own SSL certificate to the CNAME target. Sinosend handles certificate provisioning entirely. Adding a conflicting certificate at the DNS level can break your portal.
## White-label email sending
Once your custom domain is active, configure outbound email so that all delivery notifications and file alerts come from your domain.
In **Settings → Branded Portal**, scroll to the **Email Sending** section.
Type the email address you want to use as the sender — for example, `noreply@yourcompany.com` or `files@yourcompany.com`.
Sinosend displays the DNS records required to authenticate outbound mail from your domain. Add these to your DNS provider:
* **SPF record** — authorises Sinosend's mail servers to send on behalf of your domain.
* **DKIM record** — cryptographically signs outgoing emails to prevent spoofing.
Your DNS provider may also support a DMARC policy — Sinosend provides a recommended DMARC record value.
Click **Verify Email Settings**. Once Sinosend confirms the DNS records are in place, all outbound emails switch to your domain. Existing queued emails are not affected.
## Customise your portal appearance
### Logo
Upload your company logo under **Branded Portal → Appearance → Logo**. Recommended dimensions: at minimum 200 × 60 px, PNG or SVG with a transparent background. The logo appears at the top of every download page and in email headers.
### Background
Choose one of the following background options:
* **Solid colour** — pick any hex colour using the colour picker.
* **Gradient** — set a two-colour gradient with direction control.
* **Custom image** — upload a full-bleed background image (minimum 1920 × 1080 px, JPG or PNG).
### Profile image
Upload a profile or avatar image that appears alongside the sender name on download pages. Square images of at least 400 × 400 px work best.
### Brand colours
Set your primary and accent brand colours. These apply to buttons, links, and interactive elements across the portal.
### Custom CSS
For precise control over every visual detail, paste custom CSS into the **Custom CSS** editor under **Branded Portal → Appearance → Advanced**. Your CSS is injected after Sinosend's base styles, so you can override any element.
Use your browser's developer tools to inspect element class names on a test download page, then target those classes in your custom CSS.
## The recipient experience
When a recipient opens a link from your branded portal:
1. They land on a download page at your custom domain (e.g., `files.yourcompany.com/abc123`).
2. They see your logo, background, and branding — no Sinosend logo or wordmark anywhere on the page.
3. The delivery email they received came from your domain address.
4. The SSL padlock in their browser shows your domain, not Sinosend's.
The entire experience reads as a first-party product of your company.
## Best practices
Choose a subdomain like `files.` or `docs.` that recipients immediately associate with document delivery from your business.
Use the same hex colour codes, logo file, and typography you use on your website. Inconsistency undermines the professional impression.
Send a test transfer to yourself after setup to verify the logo, background, email sender, and domain all appear correctly.
Add a DMARC policy alongside SPF and DKIM to protect your domain from being spoofed in phishing emails.