Month: November 2021

Test Mail Server for Inbound TLS

Here's how to test if a mail server supports TLS using a windows pc: nslookup> set q=mx> google.comThe results:google.com   MX preference = 100, mail exchanger = google.com.s9a1.psmtp.comgoogle.com   MX preference = 300, mail exchanger = google.com.s9b1.psmtp.comgoogle.com   MX preference = 200, mail exchanger = google.com.s9a2.psmtp.comgoogle.com   MX preference = 400, mail exchanger = google.com.s9b2.psmtp.com> exittelnet google.com.s9a1.psmtp.com 25After connected type:ehlo google.comIf … Continue reading Test Mail Server for Inbound TLS

Understanding the “Nines of Availability”

If you’ve spent any amount of time in the tech field you’ve probably heard of the “Nines of Availability”. Availability is usually expressed as a percentage of uptime in a given year. The following table shows the downtime that will be allowed for a particular percentage of availability, presuming that the system is required to … Continue reading Understanding the “Nines of Availability”