The users may configure a bunch of filter rules. There are two kinds of settings: settings configured by a
config directive in the file "filterconf" or settings configured by it's own file. If the setting is not configured
in the user directrory Qsmtpd will take the value from the domain directory. If there is no domain setting also
the global one is taken if the setting is marked "global".


Filterconf settings

See filterconf(5) man page.

List of files:

There are 4 basic types of files:
-address files
	These files can contain 4 types of entries:
	1) complete mail addresses: entire from address must match this one
	2) @domain: from domain must match string, "@aol.com" would block "foo@aol.com" but not "foo@bar.aol.com"
	3) no '@' at all: block everything from this domain and subdomains, the character in MAIL FROM before the match
	   must be '.' or '@' so "aol.com" would reject "foo@aol.com" and "foo@bar.aol.com" but not "foo@no-aol.com"
	4) beginning with '.' and no '@': block everything ending with string, so ".aol.com" would block every subdomain
	   of aol.com, but not aol.com itself
-domain files
	These files can contain 2 types of entries (which will look a bit familar *g*):
	1) see #3 above
	2) see #4 above
-blocklist files
	Every entry in this type of file is the name of one blocklist, not beginning with a '.'. These files are used
	for various blocklists, e.g. an entry of "dsn.rfc-ignorant.org" in "namebl" would lead to a query of
	"rossmann.de.dsn.rfc-ignorant.org" if the sender address is "something@rossmann.de"
-IP match files
	These files exist in 2 versions, one version for IPv4 addresses with record length 5 and the other for IPv6 addresses
	with record length 17. The first 4 (16) bytes are a netmask for the IP address, the last byte is the length of the
	netmask. The minimum value of the length byte is 8, the maximum 32 (128). The file is rejected if the length is not
	a factor of the record length.

badcc:			[address]

badmailfrom:		(global) [address]
goodmailfrom:		(global) [address]

dnsbl:			(global) [blacklist]
whitednsbl:		(global) [blacklist]
dnsblv6:		(global) [blacklist]
whitednsblv6:		(global) [blacklist]

badhelo:		(global) [domain]

ipbl:			(global) [IPv4 match]
ipwl:			(global) [IPv4 match]
ipblv6:			(global) [IPv6 match]
ipwlv6:			(global) [IPv6 match]

rspf:			(global) [blacklist]
spfstrict:		(global) [domain]
ignorespf:		(global) [domain]

namebl:			(global) [blacklist]