Set Up Mail DNS

Email DNS records ensure your messages are delivered correctly, securely, and reliably. Just like for your website, the right DNS records need to be in place — otherwise emails may fail to deliver or land in spam.

The records below are the four essentials: A, SPF, DKIM, and DMARC.

If you're using OS Cloud's nameservers, you can skip these steps. For improved deliverability, we still recommend enabling DKIM and adding a DMARC record.

A record (IPv4)

The A record points your mail subdomain to your mail server's IPv4 address. You can find this IP in the OS Cloud panel under "At a glance" or under your domain settings.

Type	Hostname	Value
A	mail.yourdomain.com	Mail server IP from the panel

SPF

SPF (Sender Policy Framework) specifies which mail servers are allowed to send emails on behalf of your domain. It prevents spoofing and improves deliverability.

OS Cloud uses Mailgun for sending and receiving email, so Mailgun must be included in your SPF record as an authorised sender.

Type	Hostname	Value
TXT	@	v=spf1 include:mailgun.org ~all

DKIM

DKIM (DomainKeys Identified Mail) uses cryptographic signatures to verify the sender's identity and confirm that emails weren't tampered with in transit. DKIM is stored as a TXT record.

Enable DKIM in OS Cloud

1. Go to Websites in the left sidebar.
2. Select the website you want to configure.
3. Open Domains in the top menu and select the domain.
4. Scroll to Email Authentication and toggle DKIM to On.
5. If you're using OS Cloud nameservers, wait for the validation to complete.

If your DNS is hosted elsewhere, follow the on-screen instructions and paste the generated DKIM key into your DNS provider. The record will look like this:

Type	Hostname	Value
TXT	hostingcp._domainkey	Generated DKIM key

DMARC

DMARC (Domain-based Message Authentication, Reporting, and Conformance) protects your domain against phishing and spoofing. It works together with SPF and DKIM to make sure only authorised servers send emails on your behalf.

Type	Hostname	Value
TXT	_dmarc	v=DMARC1; p=none; rua=mailto:example@yourdomain.com

DMARC uses three key tags:

• v — DMARC version (always DMARC1, currently the only valid version).
• p — The policy for failed emails:
  • none — No action taken for failed messages.
  • quarantine — Failed messages are sent to the spam/junk folder.
  • reject — Failed messages are blocked and never reach the recipient.
• rua — Email address where DMARC reports are sent (e.g. your DNS registrar or business address).

Be careful with strict DMARC policies (quarantine or reject) — they can block legitimate emails if SPF or DKIM is misconfigured. Start with p=none to monitor before enforcing.