`mynetworks`

This parameter specifies the list of networks that are local to this machine. The list is used by the anti-UCE software to distinguish local clients from strangers. See `permit_mynetworks` and `smtpd_recipient_restrictions` in the SMTP configuration.

The default is a list of all networks attached to the machine: a complete class A network (X.0.0.0/8), a complete class B network (X.X.0.0/16), and so on. If you want stricter control, specify a list of network/mask patterns, where the mask specifies the number of bits in the network part of a host address. You can also specify the absolute pathname of a pattern file instead of listing the patterns here.