This is the command fdnsmx that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
fdnsmx - resolve an MX record of a hostname
fdnsmx will attempt to look up a single MX record for hostname. If one is found, it is
printed to standard output and the program exits with return code 0. If not, nothing is
printed and the program exits with return code 1.
Use fdnsmx online using onworks.net services