Why Emails Land in Spam

Rarely just one thing — usually a few smaller issues stacking up.

The most common causes

Sending from a public domain. Missing authentication. Poor-quality list. Sudden volume spikes. Spam-trigger language. Damaged sender reputation (complaints above ~0.3%, bounces above ~5%). Misleading subject lines. No unsubscribe option. Invalid or risky recipients (role-based addresses).

Fixing it

Content: ~60/40 text-to-image, subject lines under ~50 characters, run through Mail-Tester aiming above 8/10.

List quality: double opt-in, remove/pause 90+ day non-engagers or run a re-engagement campaign first.

Sending pattern: recovering from a spam problem — start with 100–500 emails to engaged contacts, scale gradually.

Monitoring: Google Postmaster Tools, Sender Score, MXToolbox periodically.

What to expect

Small improvements within a week or two; a genuinely damaged reputation can take two to three months.