8.8 Things to Try

• Try feeding sendmail an extremely long address in rule-testing mode, something like a.a.a... with 100 a and dot characters. What does this tell you about the limit on the size of the workspace? Is this a limit of tokens or of characters?

• Look through your system sendmail.cf file for all lines that declare rule sets ( S lines). Are there any that have no rules ( R lines) associated with them? Do the comments near them explain clearly why no rules are present?

• What happens if you use spaces rather than tabs to separate the LHS from the RHS of rules? Is the error message clear? What happens if the RHS is separated from the comment with spaces instead of tabs? How does this illustrate the importance of testing all new rules with rule-testing mode?

• Minimum matching is one of the most misunderstood aspects of rules. If you are still the tiniest bit confused about this topic, review Section 8.7.2, "Minimal Matching" and possibly leap ahead to Section 28.5.1, "Minimum Matching" .