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.
The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total amount of visible light emitted by a source.he luminous intensity would still be one candela in those directions that are not obscured. The lumen can be thought of casually as a measure of the total amount of visible light in some defined beam or angle, or emitted from some source.