Всем доброго дня!
Ни как не могу понять в чем трабл. Есть почтовый сервер, установлен Sendmail 8.13.4+SASL+SSL, при получении тела письма от клиента жутко тормозит.
Письмо едет туда со скоростью около 80 кб/сек. При этом FTP, POP и другие сервисы работают на ура(скорость передачи - как и должна быть в локалке).
tcpdump показывает что передача тела письма идет с перерывами на 0,1 сек:
14:53:40.602087 myserver.ru.smtp > myworkstation.3801: . ack 8301 win 57960 (DF)                                                
14:53:40.604148 myworkstation.3801 > myserver.ru.smtp: . 8301:9561(1260) ack 504 win 17137 (DF)                                
14:53:40.605218 myworkstation.3801 > myserver.ru.smtp: . 9561:10821(1260) ack 504 win 17137 (DF)                                
14:53:40.605230 myserver.ru.smtp > myworkstation.3801: . ack 10821 win 56700 (DF)                                              
14:53:40.606290 myworkstation.3801 > myserver.ru.smtp: . 10821:12081(1260) ack 504 win 17137 (DF)                              
14:53:40.606304 myserver.ru.smtp > myworkstation.3801: . ack 12081 win 57960 (DF)                                              
14:53:40.607553 myworkstation.3801 > myserver.ru.smtp: . 12081:13341(1260) ack 504 win 17137 (DF)                              
14:53:40.608717 myworkstation.3801 > myserver.ru.smtp: . 13341:14601(1260) ack 504 win 17137 (DF)                              
14:53:40.608727 myserver.ru.smtp > myworkstation.3801: . ack 14601 win 56700 (DF)                                              
14:53:40.609788 myworkstation.3801 > myserver.ru.smtp: . 14601:15861(1260) ack 504 win 17137 (DF)                              
14:53:40.609802 myserver.ru.smtp > myworkstation.3801: . ack 15861 win 57960 (DF)                                              
14:53:40.610399 myworkstation.3801 > myserver.ru.smtp: P 15861:16493(632) ack 504 win 17137 (DF)                                
                                                                                                                                
14:53:40.702088 myserver.ru.smtp > myworkstation.3801: . ack 16493 win 57960 (DF)                                              
14:53:40.704163 myworkstation.3801 > myserver.ru.smtp: . 16493:17753(1260) ack 504 win 17137 (DF)                              
14:53:40.705231 myworkstation.3801 > myserver.ru.smtp: . 17753:19013(1260) ack 504 win 17137 (DF)                              
14:53:40.705240 myserver.ru.smtp > myworkstation.3801: . ack 19013 win 56700 (DF)                                              
14:53:40.706301 myworkstation.3801 > myserver.ru.smtp: . 19013:20273(1260) ack 504 win 17137 (DF)                              
14:53:40.706315 myserver.ru.smtp > myworkstation.3801: . ack 20273 win 57960 (DF)                                              
14:53:40.707577 myworkstation.3801 > myserver.ru.smtp: . 20273:21533(1260) ack 504 win 17137 (DF)                              
14:53:40.708791 myworkstation.3801 > myserver.ru.smtp: . 21533:22793(1260) ack 504 win 17137 (DF)                              
14:53:40.708801 myserver.ru.smtp > myworkstation.3801: . ack 22793 win 56700 (DF)                                              
14:53:40.709885 myworkstation.3801 > myserver.ru.smtp: . 22793:24053(1260) ack 504 win 17137 (DF)                              
14:53:40.709899 myserver.ru.smtp > myworkstation.3801: . ack 24053 win 57960 (DF)                                              
14:53:40.710473 myworkstation.3801 > myserver.ru.smtp: P 24053:24685(632) ack 504 win 17137 (DF)                                
                                                                                                                                
14:53:40.802089 myserver.ru.smtp > myworkstation.3801: . ack 24685 win 57960 (DF)                                              
14:53:40.804154 myworkstation.3801 > myserver.ru.smtp: . 24685:25945(1260) ack 504 win 17137 (DF)                              
14:53:40.805224 myworkstation.3801 > myserver.ru.smtp: . 25945:27205(1260) ack 504 win 17137 (DF)                              
14:53:40.805233 myserver.ru.smtp > myworkstation.3801: . ack 27205 win 56700 (DF)                                              
14:53:40.806294 myworkstation.3801 > myserver.ru.smtp: . 27205:28465(1260) ack 504 win 17137 (DF)                              
14:53:40.806308 myserver.ru.smtp > myworkstation.3801: . ack 28465 win 57960 (DF)                                              
14:53:40.807459 myworkstation.3801 > myserver.ru.smtp: . 28465:29725(1260) ack 504 win 17137 (DF)                              
14:53:40.808723 myworkstation.3801 > myserver.ru.smtp: . 29725:30985(1260) ack 504 win 17137 (DF)                              
14:53:40.808732 myserver.ru.smtp > myworkstation.3801: . ack 30985 win 56700 (DF)                                              
14:53:40.809794 myworkstation.3801 > myserver.ru.smtp: . 30985:32245(1260) ack 504 win 17137 (DF)                              
14:53:40.809808 myserver.ru.smtp > myworkstation.3801: . ack 32245 win 57960 (DF)                                              
14:53:40.810520 myworkstation.3801 > myserver.ru.smtp: P 32245:32877(632) ack 504 win 17137 (DF)

Например, у FTP таких разрывов нет...
В настройках и документации Sendmail ничего умного на сей счет не нашел.
Бьюсь уже неделю.
Подскажите как с этим бороться??