  Aims. We perform a statistical study of the relations between the properties
of solar energetic electron (SEE) events measured by the MESSENGER mission from
2010 to 2015 and the parameters of the respective parent solar activity
phenomena to identify the potential correlations between them. During the time
of analysis MESSENGER heliocentric distance varied between 0.31 and 0.47 au.
Results. There is an asymmetry to the east in the range of connection angles
(CAs) for which the SEE events present the highest peak intensities, where the
CA is the longitudinal separation between the footpoint of the magnetic field
connecting to the spacecraft and the flare location. Based on this asymmetry,
we define the subsample of well-connected events as when -65$^{\circ}\leq$ CA
$\leq+33^{\circ}$. Conclusions. Based on the comparison of the correlation
coefficients presented in this study using near 0.4 au data, (1) both flare and
shock-related processes may contribute to the acceleration of near relativistic
electrons in large SEE events, in agreement with previous studies based on near
1 au data; and (2) the maximum speed of the CME-driven shock is a better
parameter to investigate particle acceleration related mechanisms than the
average CME speed, as suggested by the stronger correlation with the SEE peak
intensities.
