Fixes
SPF, DKIM and DMARC explained without the headache
Three short records decide whether inboxes trust your emails. Here is what each one does, with simple examples you can share with your developer.
Email deliverability, explained plainly
Get your emails out of spam and into the inbox.
Clear guides to the settings, rules and habits that decide where your emails land. For business owners, newsletter writers and the developers who help them.
Core guides
The fundamentals every sender should have in place.
Sender rules
The Gmail, Yahoo and Outlook sender rules, explained simply
The big inbox providers now have clear rules for anyone sending marketing email. Here is what they require, who they apply to and how to check you comply.
List health
Why you should clean your email list, and how to do it
A smaller list can earn you more. Learn how removing inactive contacts saves money, protects your sender reputation and lifts your results.
Recently reviewed
Mailbox providers change their rules. These guides were checked most recently.
| Guide | Last reviewed |
|---|---|
| Why your emails go to spam, and how to fix it | August 4, 2026 |
| How to warm up a new domain or email tool before big sends | May 12, 2026 |
| SPF, DKIM and DMARC explained without the headache | February 17, 2026 |
| How to check if your domain is blacklisted, and how to get removed | January 27, 2026 |
| Why you should clean your email list, and how to do it | September 9, 2025 |
| The Gmail, Yahoo and Outlook sender rules, explained simply | June 3, 2025 |