Why Your Emails Land in Spam (and How to Fix It)

You sent a perfectly ordinary email and it landed in spam. Frustrating — and rarely random. Mailbox providers score every message on dozens of signals. Here are the ones that actually move the needle, in roughly the order they matter.

1. Authentication is missing or misaligned

If your SPF, DKIM and DMARC aren't set up and aligned, you start every send with a strike against you. This is the first thing to fix, and the easiest.

2. Your IP or domain reputation is poor

Reputation is earned over time by sending wanted mail to engaged recipients. A brand-new domain or a shared IP that others have abused both drag you down. A dedicated IP you control, warmed up gradually, fixes this.

3. You're sending to people who didn't ask

This is the big one. Purchased or scraped lists are full of spam traps and uninterested recipients who mark you as spam. High complaint rates teach mailbox providers to filter you — permanently. Send only to people who opted in.

4. Your content trips filters

• Spammy subject lines (ALL CAPS, "FREE!!!", excessive punctuation).
• A single giant image with almost no text.
• Link shorteners and mismatched link domains.
• No visible unsubscribe link.

5. Low engagement over time

If recipients never open or click, providers infer your mail isn't wanted. Prune inactive subscribers, send relevant content, and keep a consistent cadence.

The fix, as a checklist

1. Set up SPF, DKIM and DMARC, and confirm alignment.
2. Use a dedicated IP and warm it up — see our warm-up guide.
3. Mail only opted-in recipients; remove hard bounces immediately.
4. Write like a human, include a plain-text part and an unsubscribe link.
5. Watch your complaint and bounce rates and act on them.

Do these consistently and the inbox stops being a mystery. Our SMTP plans handle the infrastructure side; the list and content are yours to keep clean.