Установлен Postgrey.
Запускам сервис:
service postgrey start
Starting postgrey service:                                             [ DONE ]
Проверяем работу сервиса:
service postgrey status
postgrey is dead, but stale PID file exists
Повторный запуск сервиса выдает ошибку:
service postgrey start
Starting postgrey service: Pid_file already exists for running process (9302)... aborting
ERROR: Pid_file already exists for running process (9302)... aborting   [FAILED]
Если запускать Postgrey "вручную":
postgrey -v --inet=127.0.0.1:60000 --lookup-by-host
2013/11/03-23:23:05 postgrey (type Net::Server::Multiplex) starting! pid(9140)
Binding to TCP port 60000 on host 127.0.0.1 with IPv4
Setting gid to "453 453"
Setting uid to "469"
никаких ошибок не выдает и не падает.