It is proved that if a system of exponents has the property that any function regular in a closed convex domain ¯G can be represented in an open domain G by a Dirichlet series, then any function regular only in G can be represented in G by a Dirichlet series with the same system of exponents. A study is made of the representation of functions regular in ¯G by Dirichlet series that converge in ¯G.