  A multichannel analysis of cosmic ray electron and positron spectra and of
the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON
code. This study is aimed at probing the interstellar electron source spectrum
down to E ~ 1 GeV and at constraining several propagation parameters. We find
that above 4 GeV the electron source spectrum is compatible with a power-law of
index -2.5. Below 4 GeV instead it must be significantly suppressed and the
total lepton spectrum is dominated by secondary particles. The positron
spectrum and fraction measured below a few GeV are consistently reproduced only
within low reacceleration models. We also constrain the scale-height zt of the
cosmic-ray distribution using three independent (and, in two cases, original)
arguments, showing that values of z_t < 2 kpc are excluded. This result may
have strong implications for particle dark matter searches.
