Seven ways to reduce newsletter spam problems

Originally published on jonatascastro.com. English edition translated and revised 01 Oct 2026. Historical examples are identified in the text.

An email campaign is useful only if people want to receive it and can find it. The original version of this article offered seven suggestions for keeping newsletters out of the spam folder.

Several ideas still help. Others needed a clearer explanation: adding a sender to contacts does not guarantee delivery, and avoiding a few promotional words does not solve deliverability on its own.

1. Start with permission

Send newsletters to people who chose to receive them. Explain what they are subscribing to, and avoid purchased or scraped address lists.

Make unsubscribing easy. Continuing to send unwanted messages damages trust and increases the likelihood of complaints.

2. Set a predictable rhythm

Tell subscribers how often you plan to write, then choose a schedule you can sustain. The old article suggested sending at least once a month, but that is not a universal rule.

A useful monthly email may work well for one audience; another may prefer a different rhythm. Relevance and expectations matter more than a fixed calendar interval.

3. Check authentication and delivery signals

Before sending, confirm that your email provider has configured the domain's authentication correctly. SPF, DKIM, and DMARC help receiving systems evaluate whether a message is authorized.

Watch bounces, complaints, and provider feedback. A content-scoring tool can catch obvious problems, but its score is not a guarantee of inbox placement.

Google documents its requirements in the Gmail email sender guidelines, including additional requirements for bulk senders. Use your provider's setup instructions alongside those guidelines.

4. Write clear, honest messages

Use an accurate subject line and send the material you promised. Avoid misleading urgency, disguised promotions, and links that make the destination difficult to understand.

There is no universal list of forbidden words that makes a message safe. The sender's reputation, authentication, recipient feedback, and the message itself all matter.

5. Make your sender recognizable

Use a consistent sender name and a monitored reply address. Encourage readers to reply if a response would be useful.

Subscribers may choose to add you to their contacts or mark a legitimate message as “not spam.” Those actions can help in some circumstances; they do not guarantee that every future message will reach the inbox.

6. Preview the message in different clients

Check the email on mobile as well as desktop. Test links, readable text, image alternatives, and the unsubscribe control. Keep the layout simple enough to remain useful when images are blocked.

A message that looks good in one email client may render differently in another.

7. Protect trust

Avoid exaggerated claims, deceptive offers, and content that does not match the reason someone subscribed. Make it clear who is sending the message and why the recipient is receiving it.

Good deliverability depends on more than a technical setup. A newsletter people recognize and value gives them fewer reasons to mark it as spam.

For the broader relationship behind an email campaign, see lead management for affiliate marketing.