Custom Mail Hostnames

SMTP Zen lets you replace the shared server hostname (for example orion.smtpzen.com) with a branded mail.yourdomain.com endpoint. Plan Manager makes available a Custom Hostname quick action per domain.

1. Make sure the domain lives in your plan

Add the domain inside Client Area → Plan Manager → Domains. If the domain is not listed there, the SSL tools and host checks will skip it.

2. Grab the exact server hostname

Open Plan Manager → Domains, pick the domain, and click Custom Hostname in the quick actions row. The modal shows the server hostname assigned to your plan with a copy button and step-by-step instructions tailored to the selected domain.

3. Create the DNS record

1. Sign in to the DNS provider for the domain.
2. Add a CNAME record named mail that points to the hostname shown inside the Custom Hostname modal (for example orion.smtpzen.com).
3. Save and wait for propagation. Most providers update within a few minutes, but some take longer.

Only the mail host is recognized. Other hostnames will be ignored by the SSL manager. Do not point the CNAME to another alias or CDN; it must reference the server hostname we provided.

4. Verify readiness in Plan Manager

1. Go to Plan Manager → Domains.
2. Choose Manage SSL in the header actions.
3. The modal lists every mail.domain it detects. Once your DNS resolves to the correct IP, the status badge flips to DNS ready. If it still shows DNS missing, double-check the record and TTL.

The check is the same one we run before issuing certificates, so you can rely on it to tell you whether propagation is complete.

5. Issue the certificate

When at least one domain shows DNS ready, click Issue certificates. SMTP Zen will request Let’s Encrypt certificates for those mail hosts and install them on the mail cluster. Successful domains appear in the results list with “Certificate issued.” You can re-open this modal anytime to reissue if the certificate expires or DNS changes.

6. Update mail clients

After the certificate succeeds:

• Use mail.yourdomain.com as the IMAP/POP/SMTP hostname in desktop and mobile clients or in your app or website.
• Keep the same ports, usernames, and passwords you already use.
• Webmail continues to work from the default link, but desktop/mobile clients can now use your branded host.

If the SSL status goes back to DNS missing (for example after moving DNS providers), repeat the steps above to avoid certificate warnings.

Troubleshooting tips

• Run the Manage SSL check again after changing DNS; it uses public resolvers (1.1.1.1 and 8.8.8.8), so it reflects the public view rather than your local cache.
• Make sure no CDN or proxy sits in front of mail.domain - the record must point directly to the SMTP Zen server IP so we can prove control to Let’s Encrypt.
• Until the DNS and SSL steps are done, keep using the default hostname (*.smtpzen.com) in your clients to avoid TLS warnings.