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Why we picked it This is the one guide that walks the full technical stack in plain language: SPF, DKIM, DMARC, domain warmup timelines, and the spam and bounce thresholds Gmail and Outlook now enforce. It is written by a cold email platform, so read the product mentions with that in mind, but the DNS and warmup fundamentals apply no matter what you send with. A good starting point if your emails are quietly landing in spam and you do not yet know why.
Email Deliverability Guide: SPF, DKIM, Warmup and Everything That Gets You to the Inbox
From Smartlead by Satwick Ghosh (Smartlead)
- SPF, DKIM, and DMARC are three DNS records, not optional. Gmail and Outlook now reject or spam bulk senders who skip them.
- A new sending domain needs 3 to 6 weeks of warmup before real outreach. There is no shortcut, and skipping it is the most common reason first campaigns die in spam.
- Watch your spam complaint rate (keep it well under a fraction of a percent) and bounce rate (under 2 percent) in Google Postmaster Tools, because reputation damage is hard to undo.