How we write and check our guides

Primary sources first

Every technical statement in a guide is checked against the people who define or operate the system:

• Standards: IETF RFCs on rfc-editor.org, for example RFC 5321 (SMTP), RFC 7208 (SPF), RFC 6376 (DKIM), RFC 9989 (DMARC) and RFC 8461 (MTA-STS).
• Platforms: Microsoft Learn for Microsoft 365 and Exchange, Google's Workspace Admin Help for Google Workspace, and cPanel's own documentation.
• Threat data: government and industry sources such as the FBI's Internet Crime Complaint Center (IC3), CISA, NIST and the FTC.

We link each source in the text and list them all at the end of the guide. We don't cite a vendor blog when the standard or the platform's own documentation says the same thing.

Numbers we don't invent

We never make up statistics, customers or testimonials. A number in a guide comes from one of three places:

1. A named primary source, with its year.
2. Our own research on the top 1,000 websites, with its method, date and limitations published.
3. Anonymized totals from our own filtering service, labeled as such with the date range.

If we can't verify a figure, we leave it out.

Honest about limits

Email security is full of half-truths, so we state limitations plainly: an MX lookup can't prove mail is filtered, DMARC doesn't stop lookalike domains, and a DKIM selector we can't find is unknown, not broken. When a built-in feature is good enough, we say so.

Dated and kept current

Each guide shows when it was last updated. Platform screens and policies change, especially at Microsoft and Google, so we re-check guides when a source changes and at least twice a year. When we change a guide in a way that matters, we update its date.

Corrections

If you find an error, email support@iblockspam.com. We correct verified mistakes promptly and don't quietly rewrite history: significant corrections are noted on the page.

Independence

iBlockSpam is a product of BroadNet. Our guides are written to be useful even if you never use our service, and the steps in them work with any reputable filter or none. Where we mention our own product, it's at the end and clearly marked.

AI assistants and reuse

You're welcome to quote our guides with attribution and a link. To help AI answer engines cite us accurately, we publish a machine-readable index at /llms.txt.