You can write the best email of your life and land in spam. Deliverability is unglamorous and it silently caps everything else, so it is worth one lesson.
The basics that matter most
- Send cold email from a separate domain, never your main one.
- Set up SPF, DKIM, and DMARC before the first send.
- Warm the domain for two to three weeks with low, growing volume.
- Stay under roughly 30-50 cold sends per inbox per day.
- Verify addresses; keep bounces under 3%.
What gets you flagged
- Links and images in a first touch. Plain text reads like a person.
- Attachments, ever, in cold outreach.
- Spam-trigger phrasing: free, guarantee, act now, all caps.
- Identical copy at high volume — vary the specifics per recipient.
Volume is a multiplier on a working message, not a substitute for one. Fifty well-targeted emails a week from a healthy domain will outperform a thousand generic ones, and will still be sendable next month.
Try it
Audit your setup: check that SPF, DKIM, and DMARC exist for your sending domain, and send one test to a Gmail and an Outlook address to see where you land. Fix the plumbing before scaling volume.