#1
Can someone explain to me why this happens..

I can strum all my strings except for the low E and then mute them and my low E will ring.. it's not extremely loud but it's loud enough to be annoying when playing.
#2
I think your low e has too low action. What guitar, strings, and tuning do you use?
Gear:

Guitars: Ibanez SV5470F, Ibanez Xpt700, Fender MIM Standard Stratocaster ('04-'05), Jackson Ps-2
Ashton AG200,
Amps: ENGL E530, Bugera 6262-212,
FX: TC Electronics G-major 2, Behringer EQ700, Morley Volume / Wah
#3
Schecter C1+, whatever strings came stock with the guitar.. so not sure, and E standard.

The string also has a little fretbuzz around like 1-5.
#4
Check if the low E is a lot lower than the other strings. Also, might be that you need to adjust your truss rod a bit. There's lots of tutorials on the net about how to do it and what it affects.
Gear:

Guitars: Ibanez SV5470F, Ibanez Xpt700, Fender MIM Standard Stratocaster ('04-'05), Jackson Ps-2
Ashton AG200,
Amps: ENGL E530, Bugera 6262-212,
FX: TC Electronics G-major 2, Behringer EQ700, Morley Volume / Wah