A microscopic model for the ultrafast photoinduced electron-transfer process in solutions of oxazine-1 in N,N-dimethylaniline (DMA) is presented. Translational and rotational motions of the solvent molecules are treated classically by molecular dynamics simulations. Along the trajectory, the energy gaps between the optical excitation and the charge transfer states involving the first solvation shell are calculated quantum mechanically, together with the corresponding electron-transfer matrix elements. The first solvation shell consists of similar to 20 DMA molecules and is rather stable with a decay time of similar to 20 ps. The calculated fluctuations of energy Saps and couplings occur on a time scale of about 0.3-1 ps, considerably slower than the fastest experimentally observed decay time of 70 fs. At most points along the trajectory, at least one DMA molecule is in a position and orientation that gives large electron transfer matrix elements up to 0.08 eV. The coupling of the electron transfer to intermolecular vibrations is investigated with a quantum chemical approach combining ab initio normal modes of the individual molecules and semiempirical electronic structure calculations. Several modes of electron acceptor and donor are identified that act efficiently as accepting modes.