What is the best way to lookup MX records for a domain from the command line?
3 options, in order from least to most verbose:
host -t mx mydomain.com nslookup -q=mx mydomain.com dig -t mx mydomain.com
The difference is largely a matter of personal preference; I tend to use
host, but if you want full details about exactly what you're getting back from the server,
dig is the way to go.
nslookup -q=mx mydomain.com
dig -t mx mydomain.com will work as well.