Email Marketing Best Practices

Marketing domain, authentication, and domain hygiene for best deliverability

This guide outlines commonly used steps for setting up email marketing in a way that supports reliable delivery. Most users follow a similar process to help ensure their emails reach inboxes rather than spam folders.
As you work through the steps below, it helps to keep in mind which email marketing platform you’ll be sending from (for example, Mailchimp, ActiveCampaign, or Constant Contact).

What you’ll need

• Access to your DNS provider (where your domain records are managed)

• Admin access to your email marketing platform (ESP)

• The “from” email address you want to send from (e.g., news@updates.yourdomain.com)

Step 1: Choose a marketing sending domain

Many businesses separate marketing email from their primary corporate email to reduce risk and improve visibility into performance.

Common approaches

• Using a subdomain

  • Example: updates.yourdomain.com or marketing.yourdomain.com

  • From address: hello@updates.yourdomain.com

  • Most users find this approach easier to manage while keeping branding consistent.

• Using a separate marketing-only domain

  • Example: yourdomainmail.com

  • This is sometimes used when a subdomain isn’t possible, but usually requires extra care to maintain trust and recognition.

Step 2: Set your sending identity (From name and From address)

Inbox providers and recipients both look for clear, recognisable sender details.

Most users choose:

• A From name that matches their brand or a real person associated with it

• A From address on the same domain or subdomain they are sending from

Addresses that discourage replies or don’t clearly match the brand often see lower engagement.

Step 3: Add email authentication records

Authentication helps mailbox providers confirm that your emails are legitimate.

SPF (Sender Policy Framework)

SPF tells inbox providers which systems are allowed to send email on your behalf. You will typically need to add an SPF record for whichever platform you are using to send the marketing emails.

• Your email platform will provide an SPF value to add to DNS.

• Most users already have an SPF record, so it’s common to merge new values into the existing record rather than creating a second one.

• Only one SPF record should exist per domain or subdomain.

DKIM (DomainKeys Identified Mail)

DKIM adds a cryptographic signature to your emails.

• Your platform will supply one or more DKIM records.

• These are added to DNS exactly as provided.

• Once verified, platforms usually show DKIM as active or authenticated.

DMARC

DMARC builds on SPF and DKIM and provides reporting on authentication results.

• Many users start with a monitoring-only policy (p=none) to collect data.

• Over time, some tighten this policy once they’re confident all sending sources are authenticated.

• DMARC records are added as TXT records in DNS.

Step 4: Keep domains and links consistent

Mailbox providers look at overall consistency when evaluating email trust.

Most users aim to align:

• The sending domain

• Link tracking domains (if supported by the platform)

• Image hosting domains

Using clearly related domains throughout your emails often helps avoid mixed signals.

Step 5: Prepare your contact list

List quality plays a major role in ongoing deliverability.

Most users:

• Email contacts who have clearly opted in

• Remove invalid addresses automatically

• Separate engaged and unengaged contacts

• Avoid uploading old or unverified lists without cleaning them first

Poor list quality is one of the most common causes of spam filtering.

Step 6: Gradually ramp up sending on new domains

New domains and subdomains don’t have a sending history yet.

Most users:

• Start by emailing their most engaged contacts

• Increase volume gradually over several sends

• Monitor results before sending to larger segments

Sudden high-volume sends from a new domain often lead to filtering issues.

Step 7: Confirm bounces, complaints, and unsubscribes are handled automatically

Most modern email platforms manage this by default, but it’s still worth checking.

Users typically ensure:

• Hard bounces are suppressed immediately

• Spam complaints stop future sends to that contact

• Unsubscribes are processed instantly and without friction

Step 8: Test before sending broadly

Before a large send, many users:

• Send test emails to inboxes on different providers (e.g. Gmail, Outlook)

• Confirm links, images, and formatting are correct

• Check that authentication appears to be passing in inbox headers

Step 9: Maintain ongoing domain hygiene

Deliverability is influenced by long-term behaviour, not just initial setup.

Most users regularly:

• Remove or suppress contacts who never engage

• Keep sending patterns consistent

• Review engagement trends and investigate sudden drops

• Adjust frequency or segmentation when engagement declines

Step 10: Common issues and what to check

Authentication not passing

• DNS records may be missing, incomplete, or still propagating

• SPF records may need to be merged rather than duplicated

• DKIM records may not match exactly what the platform provided

Emails landing in spam

• Sending too much volume too quickly

• Low engagement or high complaint rates

• Inconsistent domains or misleading content

Declining engagement

• Lists may include inactive contacts

• Content or frequency may need adjustment

• Segmentation may be too broad

Quick setup overview

Most users follow this pattern:

• Use a dedicated domain or subdomain for marketing email

• Authenticate with SPF, DKIM, and DMARC

• Start with engaged contacts and increase volume gradually

• Maintain list hygiene over time