EMAIL BEST PRACTICES
The 10 rules that decide whether your email lands in the inbox or the spam folder. Memorize them.
Authenticate (SPF + DKIM + DMARC)
Without all three, Gmail and Outlook treat you like a stranger. Set DMARC to p=quarantine once SPF/DKIM align.
Warm up new domains
Don't blast 10,000 emails on day one. Ramp up 50 → 100 → 250 → 500/day over 4 weeks.
Use a dedicated sending domain
Send marketing from mail.yourdomain.com — protect your root domain's reputation.
Keep your list clean
Remove hard bounces immediately. Suppress addresses that haven't opened in 90 days.
Write like a human
Avoid ALL CAPS, $$$, excessive emojis, and 'FREE!!!' — classic spam triggers.
Maintain a plain-text version
HTML-only emails look suspicious. Always include a multipart/alternative plain-text body.
One-click unsubscribe (RFC 8058)
Required by Gmail/Yahoo for bulk senders. Add the List-Unsubscribe-Post header.
Watch your complaint rate
Keep spam complaints under 0.1%. Above 0.3% and you're blacklisted.
Send at consistent volume
Spiky volume looks like a hacked account. Spread sends across days, not minutes.
Monitor blacklists weekly
Spamhaus, SORBS, Barracuda. One listing can tank your inbox rate by 40%.