# Postfix' dbm/hash files don't allow CIDR notation, netmasks
# or address ranges, but you can achieve the same end with
# regular expressions.
#
# Again: these are in PCRE notation.  But you could accomplish
# the same with POSIX RE's.  (I just don't know how.)

# 10.9.8.0 - 10.9.9.255
#/10\.9\.[89]\.\d+/          REJECT

# 10.9.8.0 - 10.9.10.255 is generally no good, but 10.9.8.7 is OK
#/10\.9\.8\.7/               OK
#/10\.9\.([89]|10)\.\d+/     554 Go away. We don't want any!

# A much more complex example of listing a (CIDR) IP range
# (If this makes your eyes cross, just ignore it for now)
# 10.33.192.0/19 = 10.33.192.0 - 10.33.223.255
#/^10\.33\.((19[2-9])|(2(0[0-9]|1[0-9]|2[0-3])))\.\d{1,3}$/    REJECT

# Postfix experimental release 20030706 contains experimental
# support for CIDR-based lookup tables, so the regexp-type lookups
# for address ranges may soon no longer be necessary.  To see if
# your version of Postfix supports CIDR-based maps, do a "man
# cidr_table" and look for "cidr" in the output of "postconf -m".