dns | KC's Blog

PowerShell Tip: How To Get All IPs Assigned to a DNS Domain

March 4, 2019March 4, 2019 Kent ChenMicrosoft

We always use command lines like PING to get the IP address assigned to a specific domain DNS. For example, to get the IP address of google.com, we use: ping google.com As you can see, this only returns one of IP addresses assigned to google.com. To get the full list of IP addresses associated with google.com, you need to use […]

Email failed to deliver to certain domains with an SMTP protocol error occurred message

December 13, 2009December 13, 2009 Kent ChenMicrosoft

It happened lately in my office that emails sent to certain domains first got delayed and then failed with a SMTP error code 4.4.7 in the final NDR. Error code 4.4.7 usually indicates that the message in the queue has expired and usually the problem is on the receiving server. However, that is obviously not the case this time. Also […]