Deliverability is plumbing, and you fix it before you touch copy. Never send cold mail from your main company domain: buy two or three lookalike .com domains, put SPF, DKIM and DMARC on each, and create two or three mailboxes per domain. Warm each mailbox for two to three weeks, starting at five sends a day and climbing to twenty five, and keep it there rather than blasting from one address. Verify every address before you send so bounces stay under 2 percent and spam complaints under 0.1 percent, because Gmail will quietly bin you above 0.3 percent. If replies are still flat after all that, your problem is the list or the copy, not the plumbing.
3 hand-picked resources, 3 link-checked. Pick how you want to dig in.
Why we picked it The clearest single page on the boring setup nobody explains to a first-time sender: why you buy secondary domains, what SPF, DKIM and DMARC actually do, and a three week warm-up schedule with real numbers rather than vague advice to go slow.
From Unify by Austin Hughes 15 min read
Open unifygtm.com →Why we picked it Gmail is the judge, so read the judge's own rules rather than a blog's summary of them. This is where the 0.3 percent spam rate ceiling, the authentication requirements and the one-click unsubscribe rule are written down by the people who enforce them.
From Google Workspace Admin Help 20 min read
Open support.google.com →Why we picked it Gives you a number to judge yourself against before you conclude the spam folder is the problem: 3.43 percent average reply rate, 5.5 percent for the top quartile. If you are near that, your deliverability is probably fine and your list is the issue.
From Instantly 20 min read
Open instantly.ai →How outbound that works reads from a different seat.
The same ground, over in Get your first customers, our Starting Up track.
The same ground, over in Grow organically & retain, our D2C track.
