Noun. 1. achromatic color-a color lacking hue; white or grey or black. achromatic colour. color, coloring, colouring, colour-a visual attribute of things that results from the light they emit or transmit or reflect; a white color is made up of many different wavelengths of light.
A good candidate for a mail host is a system that connects your systems to the outside world or to a parent domain. 1  Become superuser on the mail host system. 2  Verify the host name configuration. 3  Update. Create an entry for the new mail host in the appropriate hosts file.  Change the correct configuration 1  file. Restart and test your mail configuration.
On the Internet, hostnames may have appended the name of a Domain Name System (DNS) domain, separated from the host-specific label by a period (dot). In the latter form, a hostname is also called a domain name.