Referência para filtros de conteúdo e ou demais scripts para o Postfix.

Bounce:
64 command line usage error
65 data format error
66 cannot open input
67 user unknown
68 hostname unknown
69 service unavaiable
70 internal software error
72 critical OS file missing
73 can't create user output file
74 input/output error
76 remote error in protocol
77 permission denied
78 local configuration error

Deferrer:
71 system resource problem
75 temporary failure