DKIM Key Generator: 2048-bit Key Pair and DNS Record
Generate a DKIM RSA key pair in your browser and get the TXT record, PEM keys and install steps for OpenDKIM, Exim, cPanel and DirectAdmin.
October 6, 2026
Gmail and Yahoo Bulk Sender Requirements: 2026 Host Checklist
Gmail and Yahoo bulk sender rules for 2026: the 5,000-a-day threshold, SPF, DKIM, DMARC alignment, one-click unsubscribe, 0.3% spam rate and a host checklist.
October 6, 2026
One-Click Unsubscribe (RFC 8058) for Exim, Postfix, WordPress
Add RFC 8058 one-click unsubscribe correctly: List-Unsubscribe and List-Unsubscribe-Post headers, DKIM signing in Exim and OpenDKIM, a WordPress example and a tested endpoint.
October 6, 2026
Outlook 550 5.7.515: Fix the High-Volume Sender Rejection
Fix Outlook.com 550 5.7.515 "sending domain does not meet the required authentication level": the 5,000-a-day rule, SPF, DKIM, DMARC and alignment checks.
October 6, 2026
Emails Going to Junk in Outlook and Hotmail: Sender-Side Fix
Why your mail lands in Outlook.com or Hotmail junk and how to fix it from the sending side: authentication, IP checks, SNDS reputation, JMRP complaints and content.
October 6, 2026
Microsoft SNDS and JMRP Setup: 2026 Portal, Access and Reports
Set up Microsoft SNDS and JMRP on the 2026 portal: request IP or ASN access, the 10-month reattestation, reading filter and complaint data, and handling junk reports.
October 6, 2026
IP Warm-Up Schedule Generator for New Mail Servers
Build a day-by-day IP warm-up plan from your target volume and number of IPs, with Gmail, Microsoft and Yahoo sender requirements.
October 6, 2026
DMARCbis (RFC 9989): What Changed and Must You Edit Records?
DMARCbis (RFC 9989, 9990, 9991) explained: new np, psd and t tags, pct/rf/ri removed, the DNS tree walk, and whether you need to edit your DMARC record.
October 6, 2026
BIMI VMC vs CMC: Requirements, DMARC and Which Inboxes Show Logos
BIMI VMC vs CMC compared: trademark vs 12-month prior use, DMARC enforcement, SVG Tiny PS rules, and which mailbox providers (Gmail, Yahoo, Apple) show the logo.
October 6, 2026
MTA-STS on cPanel and DirectAdmin: Policy File and TLS-RPT
Set up MTA-STS on cPanel or DirectAdmin: create the mta-sts subdomain, host .well-known/mta-sts.txt with a valid certificate, add the DNS and TLS-RPT records and test.
October 6, 2026
MTA-STS Generator: TXT Record and Policy File
Generate the _mta-sts TXT record, the mta-sts.txt policy file and its hosting URL, with an optional TLS-RPT record.
October 6, 2026
TLS-RPT Record Generator: _smtp._tls TXT Record
Generate a TLS-RPT TXT record at _smtp._tls with mailto and https report destinations, encoded the way RFC 8460 requires.
October 6, 2026