The orbits of Mars and Earth bring the two planets as close to each other as they ever get approximately every 26 months. Mars never looks very big, much less the size of the Moon, though it can regularly be seen glimmering in the evening sky. (Basic Marswatching info can be found at a site maintained by JPL’s Jane Houston Jones.)
According to Snopes:
[The] 2007 version of this e-mail is commonly headed by the line “Two moons on 27 August.” An amusing irony is that some parts of the world won’t even see one moon the following day, as a total lunar eclipse is slated to occur on that date.
Right now Mars is on the other side of the Sun. So this is one night you won’t need to “keep watching the skies!”