If your newsletters land in spam, it is rarely the content. It is usually authentication, list hygiene or sending behaviour. Here are the six fixes that solve it in almost every case.
1. Set up SPF
SPF is a DNS text record listing the servers allowed to send mail for your domain. Without it, receiving providers cannot verify that your email really came from you, and they treat it as suspicious by default. Your email provider gives you the exact value — copy it precisely.
2. Enable DKIM
DKIM cryptographically signs each message, proving it was not altered in transit. Like SPF, it is a DNS record supplied by your sending service. Together, SPF and DKIM handle the majority of deliverability problems.
3. Add a DMARC policy
DMARC tells receiving servers what to do when SPF or DKIM fail, and it sends you reports about who is sending mail as your domain. Start with a monitoring-only policy, read the reports for a few weeks, then tighten it.
4. Clean your list
Sending to dead or unengaged addresses damages your reputation. Remove hard bounces immediately, run a re-engagement campaign for silent subscribers, and delete those who never open anything. A smaller engaged list outperforms a large cold one every time.
5. Send consistently
Sudden spikes look like spam. Send on a predictable schedule, warm up new domains gradually, and avoid blasting thousands of emails from a domain that sent none last month.
6. Watch your wording and formatting
ALL-CAPS subject lines, stacks of exclamation marks, excessive red text, huge images with no text, and phrases like "act now" or "risk-free" all raise flags. Write like a person, keep a reasonable text-to-image ratio, and always include a plain-text version.
Also check
- Use double opt-in so addresses are genuinely confirmed
- Include a visible, working unsubscribe link
- Send from a real domain address, not a free webmail account
- Make sure your sending domain has a valid reverse DNS record
- Never buy or scrape lists — it is the fastest route to a blocklist
How to test
Send to test addresses at the major providers, then check where it lands. Use a free deliverability checker to verify SPF, DKIM and DMARC are passing. Confirm your domain is not on any public blocklist.
How long recovery takes
Authentication fixes work within hours. Reputation repair from bad list practices takes weeks of consistent, engaged sending. There is no shortcut — steady, wanted email is the only thing that rebuilds trust.
