Set your sender. Configuring SPF, custom domain, DKIM and DMARC

You can easily configure Mailrelay's sender authentication settings to improve inbox deliverability through SPF, custom domain, DKIM, and DMARC.

Step 1: SPF

The SPF protocol is a DNS record used to improve the security of your domain by telling anti-spam filters that messages sent from authorized IPs are authentic. This prevents identity theft and helps prevent ISPs like Hotmail, Yahoo!, and Gmail from marking your emails as SPAM.

To configure SPF, access your DNS manager or ask your hosting provider to add or update your record:

• If you already have an SPF TXT record, add this include directive: include:spf.ipzmarketing.com
• If you do not have an existing SPF record, add this complete TXT record: v=spf1 a mx include:spf.ipzmarketing.com -all

The -all tag specifies that only authorized IPs can send emails using your domain. Using more permissive tags like ~all allows external servers to send from your domain, while ?all or +all renders the protection ineffective.

You can check if your SPF record is valid in your Mailrelay account under Settings >> Email authentication.

Step 2: Custom domain

A custom domain replaces the generic Mailrelay domain in your tracking links and image URLs with your own domain name (e.g., yourdomain.ipzmarketing.com).

1. Create a new subdomain in your DNS manager (for example: newsletter.yourdomain.com or news.yourdomain.com).
2. Add a CNAME record pointing that subdomain to yourdomain.ipzmarketing.com.
3. In your Mailrelay account, navigate to Settings >> Custom domains and click Add.
4. Enter the custom domain you created (without http:// or https://) and mark it as active once created.

Verify your setup under Settings >> Email authentication.

Step 3: DKIM

A DKIM key attaches a unique cryptographic signature to your emails, validating to receiver filters that the sending domain matches the message origin.

1. In your DNS manager, create the following precise subdomain (replace yourdomain.com with your actual domain): ipz._domainkey.yourdomain.com
2. Create a CNAME record pointing that subdomain to: dkim.ipzmarketing.com. (include the trailing dot).

Verify your DKIM status under Settings >> Email authentication.

Step 4: DMARC

A DMARC record tells receiving mail servers how to handle incoming emails from your domain that fail SPF or DKIM authentication checks.

To set it up, create a TXT record in your DNS settings with the following details:

• Host / Name: _dmarc.yourdomain.com
• Value: v=DMARC1; p=none;

You can verify your DMARC setup in your Mailrelay account under Settings >> Email authentication.