Question : How to Avoid the Spam Folder

Even great emails end up in spam if you skip the basics. Here are the 8 fixes that actually move the needle on inbox placement — based on what Gmail, Outlook and Yahoo evaluate.

1. Authenticate every send

• Publish SPF, DKIM and DMARC on your sending domain.
• Move DMARC from p=none to p=quarantine once alignment is clean.
• Use a domain that matches your brand — never a free webmail address as the From.

2. Send only to opted-in contacts

• Use double opt-in for every signup form.
• Never buy lists — spam-trap addresses kill domain reputation in one campaign.
• Suppress hard bounces and inactive contacts older than 6 months.

3. Write content that doesn't trip filters

• Balanced text-to-image ratio (avoid all-image emails).
• No spammy phrases ("FREE!!!", "100% guaranteed", all-caps subject).
• Single, clean HTML — no broken tags or hidden text.
• Always include a plain-text alternative.

4. Warm up new IPs and domains

1. Start with 200-500 of your most engaged contacts.
2. Double the volume every 1-2 days.
3. Watch open and complaint rates daily for the first 4 weeks.

5. Keep complaint rate under 0.1%

• Make the unsubscribe link obvious in every email.
• Honor opt-outs immediately.
• Add a one-click List-Unsubscribe header.

Related reading:

• SPF configuration
• DKIM configuration
• DMARC record
• Double opt-in subscription