Spam-folder placement is almost never caused by a single trigger word. It is the cumulative weight of weak authentication, poor reputation, dirty lists, low engagement or sudden volume spikes. Fix those, and placement improves quickly.
The checklist
Work through these in order. The first few items fix more spam-folder problems than every content tweak combined.
Authentication and reputation
- Verify SPF, DKIM and DMARC are published, valid and aligned.
- Check Google Postmaster Tools and Microsoft SNDS for your domain reputation.
- Confirm DMARC reports show no major alignment failures from your own services.
- If reputation is poor, cut volume and rebuild over four to eight weeks of clean sending.
List and engagement issues
- Suppress hard bounces, complainers and unsubscribes, every send.
- Verify any list older than three months before mailing it.
- Remove non-openers after 90 to 180 days, depending on cadence.
- Never reactivate a dormant list with one big blast; warm it back gradually.
Content and structure
- Include both HTML and plain-text versions of every campaign.
- Include the List-Unsubscribe header (mailto and HTTPS) for one-click unsubscribe.
- Avoid all-image emails; keep a reasonable text-to-image ratio.
- Use a recognisable From name and consistent sending address.
Volume and frequency
- Keep cadence steady; avoid week-long silences followed by big sends.
- Ramp into any large send rather than firing at full volume.
- At scale, spread sends across a warmed multi-domain pool.
Frequently asked questions
Why are my emails going to spam in Gmail but not Outlook?
Providers weight signals differently. Gmail is more sensitive to engagement and complaints; Outlook leans harder on content and authentication. Look at provider-specific placement, not an overall average.
Do trigger words cause spam-folder placement?
Rarely on their own. Modern filtering is overwhelmingly behavioural. Trigger-word lists are a relic; engagement, complaints and authentication do almost all the work.
How long does it take to recover from being in the spam folder?
Two to eight weeks of clean, engaged sends. The exact time depends on how badly reputation slipped and how disciplined the rebuild is.