  We show that every automorphism of a free metabelian Lie algebra $M_n$ of
rank $n\geq 4$ over an arbitrary field $K$ is almost tame, that is, it is a
product of so-called Chein automorphisms (or one-row transformations).
Moreover, we show that the group of all automorphisms $\mathrm{Aut}(M_n)$ of
$M_n$ of rank $n\geq 4$ over a field $K$ of characteristic $\neq 3$ is
generated by all linear automorphisms, as well as one quadratic and one cubic
automorphism. The same result holds for fields of any characteristic if $n\geq
5$.
  We also show that all Chein automorphisms of lower degree $\geq 4$ and all
exponential automorphisms of lower degree $\geq 5$ are tame, which contradicts
the results of \cite{BN,OE}.
