August 01, 2026
SendGrid: setting up the authenticated domain (SPF/DKIM)
SendGrid's domain authentication rests on three delegated CNAMEs. How it works, key rotation, SPF and DKIM alignment, common mistakes and RUA verification.
Read →Blog — page 7
August 01, 2026
TLS-RPT: the encrypted transport report
TLS-RPT reports encrypted-connection failures between mail servers, the aggregate report of MTA-STS. Contents, setup, and why it comes before enforce.
Read →July 29, 2026
MTA-STS, what it is and what it's for
MTA-STS enforces SMTP transport encryption and prevents a downgrade to plaintext. What it protects, how to deploy it, and its relationship to DMARC.
Read →July 29, 2026
Authenticating Mailjet: SPF, DKIM and DMARC alignment
Mailjet: domain validation, the SPF include, the mailjet._domainkey DKIM record and DMARC alignment, plus the mistakes seen in real DNS zones.
Read →July 28, 2026
Microsoft's sender requirements (Outlook, Hotmail) in 2025
After Gmail and Yahoo, Microsoft tightened its own rules for Outlook.com and Hotmail. What's required, how it differs from Google, and how to comply.
Read →July 28, 2026
Authenticating Brevo: SPF, DKIM and DMARC alignment
Brevo without domain-aligned DKIM caps deliverability. The mail._domainkey setup, the SPF envelope question, and the final proof in the RUA reports.
Read →July 27, 2026
Enabling DKIM on Google Workspace: the step-by-step guide
DKIM is off by default on a Google Workspace domain. Generating the 2048-bit key, publishing the google._domainkey TXT, header checks and DMARC alignment.
Read →July 27, 2026
Emails going to spam despite SPF and DKIM: why
SPF and DKIM pass, DMARC is aligned, and yet the mail lands in junk. This diagnostic guide covers the causes authentication alone doesn't solve.
Read →July 26, 2026
Enabling DKIM on Microsoft 365: the step-by-step guide
Microsoft 365 signs with onmicrosoft.com by default — a signature DMARC cannot align. Defender portal, PowerShell, the two CNAMEs: the full walkthrough.
Read →July 26, 2026
Gmail deliverability: the complete guide
Why emails land (or don't) in Gmail's Primary tab. Authentication, reputation, engagement: everything that determines deliverability, explained in depth.
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