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.
The user name is a nickname, some affectation or a part of a person's real name. The @, or at symbol, separates the user name from the second part of the email address, which begins with the mail server. The mail server usually identifies the institution or company that owns the email server. The last part of the email is the top-level domain, which breaks down various websites into hierarchies. Several top-level domains include .com used for commercial businesses, .org used for non-profit agencies and groups, .edu for educational institutions and .gov for government agencies.