Cold Email Deliverability: Best Practices to Avoid Spam (Post-2024 Rules)

In February 2024, Google and Yahoo introduced stricter requirements for senders, especially bulk senders. Microsoft followed with its own requirements for high-volume senders. These rules reshaped cold email deliverability. Here's what to do.

The 2024 sender requirements in short

• Authenticate: SPF and DKIM for all senders; DMARC for bulk senders (Google defines bulk as roughly 5,000+ messages a day to Gmail).
• Keep spam complaints low: Google recommends staying under 0.1% and never reaching 0.3%.
• One-click unsubscribe for bulk marketing email, honoured within two days.
• Valid forward and reverse DNS for sending IPs.

Best practices for cold email delivery

1. Use a separate domain for cold outreach to protect your main domain.
2. Set up SPF, DKIM and DMARC (start DMARC with p=none and monitor).
3. Warm up new inboxes gradually over a few weeks.
4. Keep per-inbox volume modest; spread across inboxes if needed.
5. Verify every address; keep bounces very low.
6. Plain text, minimal links, no attachments on first touch.
7. Avoid link shorteners and heavy tracking.
8. Make opting out easy and honour it immediately.
9. Monitor Google Postmaster Tools and blocklists.

Content that triggers filters

Spam filters care more about engagement and reputation than single words, but hype ("FREE!!!", "guaranteed"), all caps and image-only emails still hurt.

If you land in spam

Pause volume, check authentication, review complaints, clean the list and restart slowly with your most engaged segment.

Related: Gmail sending limits, verify email list before outreach.