We develop a message scheduling scheme that can theoretically achieve the maximum throughput for all-to-all personalized communication (AAPC) on any given Ethernet switched cluster. Based on the scheduling scheme, we implement an automatic routine generator that takes the topology information as input and produces a customized MPI Alltoall routine, a routine in the Message Passing Interface (MPI) standard that realizes AAPC. Experimental results show that the automatically generated routine consistently out-performs other MPI Alltoall algorithms, including those in LAM/MPI and MPICH, on Ethernet switched clusters with different network topologies when the message size is sufficiently large. This demonstrates the superiority of the proposed AAPC algorithm in exploiting network bandwidths.