Admin Hub
Email is the most important and most attacked communication channel in most companies, and without clean identities neither mail routing nor permission management works. This hub collects hands-on knowledge from more than 14 years of running large mail environments: SMTP and mail flow, encryption gateways such as SEPPmail and Totemomail, the HIN mail gateway in the Swiss healthcare sector, Exchange and Microsoft 365 in hybrid scenarios, plus Active Directory, LDAP, and Microsoft Entra ID as the foundation behind it all. It also includes free tools to check your own domain and mail configuration right in the browser.
Mail DNS Check
Check a domain's MX, SPF, DKIM, DMARC, and more in seconds.
Mail Header Analyzer
Trace an email's delivery path and authentication from its header, 100% locally in your browser.
Analyze a header →Command Builder
Assemble DNS, SMTP, TLS, LDAP and network commands for PowerShell or the shell, built-ins first.
Build a command →LEG Price Calculator
Is a Swiss local electricity community worth it? Grid discount versus service fee, for consumers and solar producers.
Run the numbers →Topics in this hub
Latest articles
NewCVE-2026-104286: FortiMail Zero-Day Is Being Exploited - Workaround and Compromise Assessment
Fortinet reports a critical, actively exploited path traversal vulnerability in FortiMail 7.2 through 8.0 (CVE-2026-104286, CVSS 9.8). A patch is not yet available. The workaround disables IBE or blocks Internet access to the management interface; indicators for assessing compromise are also available.
Kiteworks: Vendor Recommends Shutdown on September 26—What Is Known So Far
Kiteworks asked its customers by email to shut down all systems on Saturday, September 26, 2026, from 4:00 a.m. to 10:00 a.m. The reason is a warning from law enforcement agencies about a possible attack. Since September 27, the recommendation has been lifted; there is no CVE or new patch. TotemoMail is not affected.
MailHeaderAnalyzer: Analyze Email Headers in PowerShell Without Network Access
Reference for the MailHeaderAnalyzer PowerShell module: parameter overview, syntax, description, examples, and parameter properties for Get-MailHeaderAnalysis and ConvertTo-MailHeaderReport, plus the output object with delivery chain, authentication results, Exchange Online classification, and all finding codes.
Mail loop with encryption gateway behind EXO - Prevent spoofing issues
If the encryption gateway (HIN in this example) is behind Exchange Online, every incoming message reaches EOP a second time: with a foreign sender domain, an invalid DKIM signature, and the gateway IP as the source. The result is a spoof verdict and junk. Four settings prevent this without disabling filtering using SCL -1: a PTR record, Enhanced Filtering disabled, a spoof exception for the gateway infrastructure, and CloudServicesMailEnabled on both connectors.
Closing a journaling gap: Exporting from Microsoft Purview and importing into Enterprise Vault
If journal reports from Exchange Online fail for several days, they cannot be generated retroactively. However, the content still exists in the mailboxes. Learn how to export it as PST through the new Purview eDiscovery, why Enterprise Vault's PST Migrator is usually not an option, and how to reimport it through the journal mailbox without displacing the active journal stream, using two generic scripts for importing, moving, and logging.
Exchange Online throttles and blocks outdated Exchange 2016 and 2019 servers starting in September 2026: How transport enforcement works
Starting in the second week of September 2026, Exchange Online requires hybrid servers to have at least the October 2025 SU; otherwise, mail flow is throttled and later blocked. Background on transport enforcement since 2023, escalation stages with SMTP codes, the report in the Admin Center, the 90-day pause via PowerShell, and why the next increase will only allow ESU customers and Exchange SE.
