sendmail, 4th Edition

Rule Sets and Lists of Rules

All rules (R lines) that follow a rule set declaration are added to and become part of that rule set:

S0
R...          ← rules added to rule set 0
SMyset
R...          ← rules added to rule set Myset
S1
R...          ← rules added to rule set 1

Rule sets need not be declared in any particular order. Any order that clarifies the intention of the configuration file as a whole is acceptable. If a rule set appears more than once in a configuration file, V8 sendmail will print a warning:

WARNING: Ruleset name redefined                 ← prior to V8.8
WARNING: Ruleset name has multiple definitions  ← V8.8 and above

and append the new rules to the old:

S0
R...          ← rules added to rule set 0
S2
R...          ← rules added to rule set 2
S0            ← warning issued
R...          ← rules appended to earlier rule set 0

Note that the warning is given in all cases prior to V8.8, but beginning with V8.8, it is issued only in -bt rule-testing mode (Overview on page 299) or if the -d37.1 debugging switch (-d37.1 on page 563) is set.

Other configuration commands can be interspersed among rule definitions without affecting the rule set to which the rules are added:

S0
R...          ← rules added to rule set 0
DUuucphost.our.domain
R...          ← rules added to rule set 0

Prior to V8.10, any rules that appeared before the first S command were added to rule set 0 by default. With V8.10 and above, sendmail rejects any rules that are not preceded with a valid rule set definition.