Restrictions on client hostnames/addresses
smtpd_client_restrictions
This parameter specifies optional restrictions on SMTP client host names and
addresses.
The default is to allow connections from any host. The following
restrictions are available:
- reject_unknown_client: reject the request if the client hostname is unknown.
- permit_mynetworks: permit if the client address matches $mynetworks .
- check_client_access maptype:mapname: look up client name, parent domains, client address,
or networks obtained by stripping octets.
Reject if result is REJECT or "[45]xx text".
Permit otherwise.
- reject_maps_rbl: reject if the client is listed under $maps_rbl_domains .
- reject: reject the request. Place this at the end of a restriction.
- permit: permit the request. Place this at the end of a restriction.
Restrictions are applied in the order as specified; the first
restriction that matches wins.
Specify a list of restrictions, separated by commas and/or whitespace.
Continue long lines by starting the next line with whitespace.
Sensible examples:
- permit_mynetworks, reject_unknown_client
- reject_maps_rbl, reject_unknown_client