Serve timer images from your client's own domain

By default every image address starts with img.emailtimer.app. A white-label domain lets a client’s campaign carry an address such as images.client.com instead, so the email does not advertise the tool behind it. It is an Agency feature on pricing: five hostnames are included, and each one after that is $2 a month.

Status on 17 September 2026

The steps on this page are built into the dashboard, and the DNS check runs. The last step, issuing a certificate for the hostname, depends on a certificate service that this deployment has not switched on yet. Until it is, a domain that passes the DNS check stops with the note “Certificate issuing is not configured on this deployment”, and does not reach Active. Nothing on this page should be sent in an email until a domain shows Active.

Add the hostname

Open Custom domains in the dashboard and add the hostname the images should come from.

It has to be a subdomain. A root domain is refused with “A root domain cannot point at us. Use a subdomain instead”, followed by a suggestion such as images.client.com. Wildcards, IP addresses and anything under emailtimer.app are refused too. One hostname can belong to only one workspace across the whole service, and a workspace can hold up to 100.

Adding a hostname registers nothing on the internet yet. It creates the row, marks it “Needs DNS”, and shows the records to create.

Create the two DNS records

The dashboard shows the exact values for your hostname, each with a copy button. Most DNS providers add the domain to whatever is typed in the Name box, so paste the short name shown beside each record rather than the full one. If the full name goes in, the record ends up at a doubled hostname and the check cannot find it.

Then choose Check DNS. DNS changes can take a few minutes to become visible, and some providers take up to an hour. Checking again costs nothing.

Ownership, then the certificate

The TXT record is checked first, deliberately. Only a hostname whose ownership has been proved is ever registered with the certificate service. Without that order, anybody could attach a certificate request to a domain they do not control.

Once the record is found, the status becomes “Issuing certificate”, and the dashboard warns: “Do not use this domain in an email until it shows as Active. Certificates usually take a few minutes.” When the certificate issues, the status becomes Active and the note reads “Serving images. Safe to use in an email.”

If the certificate is still issuing an hour later, look for a CAA record on the domain. The dashboard’s own advice is that it “needs to allow letsencrypt.org and digicert.com”. A domain behind a proxy or CDN needs proxying turned off for this record. On Cloudflare that is the grey cloud rather than the orange one.

Use the hostname in a campaign

Once a domain is Active, the dashboard offers “Copy the base URL”, which is https:// plus your hostname. Put it in place of https://img.emailtimer.app at the start of an image address, whether that address came from the publish screen, the API or a recipient list export. The rest of the address stays exactly as it was minted:

https://images.client.com/i/k7mQ2pXd.gif?w=w_8ha3fq&v=3&sig=YOUR_SIGNATURE

The signature covers the path and the query, not the host, so swapping the host does not break it. The ids and the signature above are made up.

A domain only matters for new sends. An email already delivered with img.emailtimer.app keeps using it, and nothing done to a custom domain can affect it.

Removing a domain

Removal is two different actions, and the dashboard keeps them apart.

Remove is the default. The domain “stops being offered for new image links and stops being billed”. The hostname keeps serving, so every image already sent from it keeps loading.

Stop serving takes the hostname down. In the dashboard’s words: “Every image already sent from it will stop loading, in every inbox, and that cannot be undone.” It asks you to type the hostname back before it acts. Use it only when a domain has to go dark now, such as when an agency loses a client and the client wants its name off the service.

A domain that later stops resolving because its DNS changed, or because it expired, takes every image sent from it down with it. Fix the DNS rather than removing and re-adding the domain.

Questions and answers

Which plan includes white-label domains?

Agency, at $149 a month, with five hostnames included and $2 a month for each after that. A workspace on another plan can still see and remove any domains it already has.

Can I use a root domain such as client.com?

No. A CNAME cannot sit at a root domain, so use a subdomain such as images.client.com.

Do I need to mint new addresses for a custom domain?

No. Replace the host at the start of an address you already minted. The signature does not cover the host.

What happens to sent emails if I remove a domain?

With Remove, nothing: they keep loading. With Stop serving, every image sent from that hostname stops loading, permanently.