Step by step process for setting up DMARC to ensure email security

Losing customers to spam folders? Check your DKIM setup first

If you're running a SaaS or newsletter product and emails aren't reaching users, the cause is usually authentication, not content. Gmail and Outlook both tightened sender requirements — for bulk senders specifically, you now need SPF + DKIM + a published DMARC policy, aligned records, one-click unsubscribe, and low spam complaint rates, or you risk rejection outright.
The most common single point of failure we see is DKIM: wrong selector, a key that was never actually published to DNS, or still running a legacy 1024-bit key. A DKIM Record Generator is worth using instead of hand-writing the TXT record — it's an easy place to introduce a syntax error that silently breaks signing.
There's a solid technical breakdown of the full verification chain (SPF → DKIM → DMARC → reputation) and the specific SMTP bounce codes if you want to dig in.
Use a DKIM Record Generator, then read the full guide https://www.exactverify.com/blog/why-gmail-and-outlook-reject-emails

Resourceful, but DMARC alone is not sufficient, DKIM and SPF standards are essential to configure with it.

To know why and what are the benefits, you can read this - https://compile7.org/decompile/how-to-stop-business-emails-from-landing-in-spam/