Telnet: the best email diagnositc tool 8/25/2008 8:29:00 PM Oftentimes it is very helpful to remove your mail server from the equation to see if there is an underlying network / reputation problem blocking mail flow. Here's how you can manually send a test message using the telnet command built into every operating system. You'll need to determine the name or address of your recipeints mail server. You can do this by looking up their MX record at http://mxtoolbox.com. In my example the MX record is a1.mx-route.com. Your commands are in bold below and the responses I got are in italic. Be careful, on Windows if you typo you cannot back   more...

Actual vs. Typical SMTP Response Times (Hourly)	Relative Response Today
Average SMTP Response times over the last 7 days