Spam (or Junk)

Spam (junk mail) is unsolicited bulk email, often irrelevant or deceptive, that harms user trust and sender reputation.

Definition & Examples

What is Spam?

Spam refers to unsolicited, typically irrelevant or repetitive email messages sent indiscriminately to a large list of recipients. These messages are usually sent for commercial purposes and often include fraudulent or deceptive content. Unlike legitimate email marketing, spam is sent without the recipient's consent and often uses deceptive practices to bypass filters.

Why it matters

• Reputation damage: Being flagged as spam destroys your sender reputation and reduces email deliverability

• Legal consequences: Violating anti-spam laws like CAN-SPAM can result in significant fines

• User trust: Recipients who mark your emails as spam are unlikely to engage with your brand again

• Platform penalties: Email service providers may suspend accounts that generate high spam complaints

How spam filters work

Modern spam filters use multiple detection methods:

• Content analysis: Scanning for spammy phrases, excessive capitalization, and suspicious links

• Sender reputation: Evaluating the history of your IP address and sending domain

• Authentication checks: Verifying SPF, DKIM, and DMARC records

• Engagement patterns: Monitoring open rates, click rates, and complaint rates

• Recipient behavior: Analyzing how users interact with your emails over time

Types of spam

Commercial spam

• Unsolicited promotional emails for products or services

• Misleading offers and fake discounts

• Affiliate marketing without proper disclosure

Phishing emails

• Attempts to steal personal information or credentials

• Fake emails impersonating legitimate companies

• Links to malicious websites or malware downloads

Scam emails

• Nigerian prince and inheritance scams

• Fake lottery or prize notifications

• Romance scams and catfishing attempts

How to avoid being marked as spam

Permission-based marketing

• Only email subscribers who explicitly opted in to your list

• Use double opt-in to confirm consent

• Avoid purchasing email lists or sending cold emails from your primary domain

Content best practices

• Write honest, accurate subject lines that match your email content

• Avoid spam trigger words like "FREE," "URGENT," or "ACT NOW"

• Maintain a good text-to-image ratio in your emails

• Include your company's physical address in the footer

Technical setup

• Configure proper email authentication (SPF, DKIM, DMARC)

• Use a reputable email service provider like Loops

• Monitor your sender reputation using tools like Google Postmaster

• Implement list hygiene practices

Engagement optimization

• Segment your list to send relevant content to each group

• Remove inactive subscribers who haven't engaged recently

• Make it easy to unsubscribe with one-click unsubscribe

• Monitor spam complaint rates and act quickly to address issues

What to do if marked as spam

If your emails are being marked as spam:

1. Audit your practices: Review your content, sending frequency, and list quality

2. Check your reputation: Use tools like Sender Score or Google Postmaster to assess your standing

3. Contact your ESP: Work with your email service provider to identify and resolve issues

4. Clean your list: Remove inactive subscribers and invalid email addresses

5. Reduce sending volume: Temporarily decrease email frequency while you resolve issues

6. Request whitelist: Ask engaged subscribers to add you to their safe sender list

Legal compliance

Major anti-spam laws require:

• Clear identification: Include your name and valid physical address

• Honest subject lines: Don't use misleading or deceptive subject lines

• Easy unsubscribe: Provide a clear, working unsubscribe mechanism

• Quick processing: Honor unsubscribe requests within 10 business days

• Consent documentation: Keep records showing how subscribers opted in

Common spam indicators

Filters look for these red flags:

• Subject line issues: ALL CAPS, excessive punctuation (!!!), or misleading claims

• Content problems: Poor grammar, suspicious links, or embedded forms

• Technical issues: Missing authentication, shared IP problems, or blacklisted domains

• Behavioral patterns: High bounce rates, low engagement, or rapid list growth

Related terms

• Email deliverability

• Sender reputation

• CAN-SPAM

• One-click unsubscribe

Key takeaways

• Spam damages your reputation and deliverability, making it harder for legitimate emails to reach the inbox

• Permission-based marketing and proper authentication are essential for avoiding spam filters

• Focus on engagement and relevance rather than volume to maintain a good sender reputation

• When in doubt, err on the side of caution and follow email marketing best practices