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Deliverability

Junk Folder

A folder in email clients where suspected spam emails are automatically placed instead of the inbox.

Definition

The junk folder (also called spam folder or junk mail) is a designated folder in email clients where messages flagged as spam or unwanted are automatically deposited. Spam filters analyze incoming emails and route suspicious messages to this folder to protect users from spam, phishing, and malicious content. Legitimate marketing emails can end up here if they trigger spam filters.

Why It Matters

Emails in the junk folder are rarely seen or opened. If your marketing emails consistently land in junk, your campaigns are essentially wasted. Understanding why emails get junked helps you improve deliverability and ensure your messages reach the inbox.

How It Works

Email providers analyze incoming messages using spam filters that check sender reputation, authentication, content, and engagement signals. Messages that appear suspicious are routed to junk instead of the inbox. Users can mark messages as 'not junk' to train the filter.

Best Practices

  • 1Maintain good authentication (SPF, DKIM, DMARC)
  • 2Avoid spam trigger words and excessive formatting
  • 3Send relevant content to engaged subscribers
  • 4Monitor inbox placement rates to catch issues early

Frequently Asked Questions

Ensure proper authentication, maintain list hygiene, send relevant content, and build engagement. Check if you are on any blocklists. Use spam testing tools before sending to identify potential issues.

Yes, subscribers can add you to their contacts or address book, mark your emails as 'not junk', or create a filter to always deliver your emails to the inbox. Encourage new subscribers to do this.