How to Spam Consistently Good: Mastering Email Deliverability

In the realm of email marketing, the line between effective outreach and unwanted spam is remarkably thin. Sending “good spam” – emails that consistently reach inboxes and engage recipients without triggering spam filters – requires a deep understanding of deliverability best practices, technical configurations, and audience segmentation. This article provides a practical guide to mastering these techniques, ensuring your messages consistently land where they’re intended and contribute to meaningful engagement.

Table of Contents:

• Setting Up Proper Authentication (SPF, DKIM, DMARC)
• Building and Maintaining a Clean Email List
• Optimizing Email Content for Deliverability
• Understanding and Managing Your Sender Reputation
• Monitoring and Improving Email Performance

Setting Up Proper Authentication (SPF, DKIM, DMARC)

Email authentication is the cornerstone of email deliverability. It verifies that the sender is who they claim to be, preventing spoofing and phishing attempts. Implementing SPF, DKIM, and DMARC correctly is crucial for establishing trust with email providers like Gmail, Yahoo, and Outlook. Without proper authentication, your emails are far more likely to be flagged as spam, regardless of the content or targeting.

Understanding SPF (Sender Policy Framework)

SPF defines which mail servers are authorized to send emails on behalf of your domain. It’s a DNS record that lists the IP addresses or domains that are permitted to send email. When a receiving mail server receives an email, it checks the SPF record to ensure the sending server is authorized. If not, the email may be rejected or marked as spam.

Example: Let’s say your domain is `example.com` and you send emails through your own mail server (IP address `192.0.2.1`) and through a third-party email marketing service (Mailgun, with their SPF record being `include:mailgun.org`). Your SPF record would look like this:

v=spf1 ip4:192.0.2.1 include:mailgun.org -all

Explanation:

• `v=spf1`: Specifies the SPF version.
• `ip4:192.0.2.1`: Authorizes the server with the IP address 192.0.2.1 to send emails.
• `include:mailgun.org`: Includes Mailgun’s SPF record, allowing them to send emails on your behalf.
• `-all`: Specifies that any server not listed in the SPF record is not authorized and should be rejected (hard fail). Using `~all` is a soft fail, which means the email is more likely to be accepted but could still be marked as spam. `-all` is generally preferred for better deliverability.

Practical Example: Adding an SPF record using cPanel

1. Log into your cPanel account.
2. Navigate to the “Zone Editor” or “DNS Zone Editor.”
3. Select your domain (e.g., example.com).
4. Add a new TXT record.
5. In the “Name” field, enter your domain (e.g., example.com).
6. In the “TTL” field, enter 14400 (default value).
7. In the “Record” field, enter your SPF record (e.g., v=spf1 ip4:192.0.2.1 include:mailgun.org -all).
8. Click “Add Record.”

Implementing DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to your emails, which receiving mail servers can use to verify that the email hasn’t been tampered with during transit. This signature is generated using a private key that’s stored on your mail server and a corresponding public key that’s published in your DNS record. When an email is received, the receiving server uses the public key to decrypt and verify the signature. If the signature is valid, it confirms that the email is authentic and hasn’t been altered.

Example: You’ll need to generate a DKIM key pair (private and public). The process varies depending on your email provider or server software. Mailgun, for example, provides tools to generate DKIM keys. Let’s say Mailgun generates a public DKIM key with a selector of `s1`. The corresponding DNS TXT record would look something like this:

s1._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=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