$ mpiexec -n 1 ./MailThread_main < /dev/null
MPI_THREAD_FUNNELED
In function Thread_receive
In function Thread_send
In thread_send cliclo 0 con a[99] = 100.000000
In thread_send cliclo 1 con a[99] = 100.000000
aborting job:
Fatal error in MPI_Send: Other MPI error, error stack:
MPI_Send(177): MPI_Send(buf=0xf65e5120, count=100, MPI_DOUBLE, dest=0, tag=17, MPI_COMM_WORLD) failed
MPID_Send(46): DEADLOCK: attempting to send a message to the local process without a prior matching receive
rank 0 in job 4  nettuno_32793   caused collective abort of all ranks
  exit status of rank 0: killed by signal 9