Google's Gmail Web-based email service runs on the Internet Message Access Protocol system, but it also offers Post Office Protocol mail server access.
Definition of LUMEN. 1. 2. : the bore of a tube (as of a hollow needle or catheter). 3. : a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of one candle intensity.
Used to compare two light sources to one another. See Lux definition below. Technical Definition: The lumen (symbolized lm) is the International Unit of luminous flux. A unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of one candela (see definition below) intensity.