+PH/24 Re-jigged the order of the tests in the default configuration so that the
+ tests for valid domains and recipients precede the DNS black list and CSA
+ tests, on the grounds that those ones are more expensive.
+
+PH/25 Exim was not testing for a space following SMTP commands such as EHLO
+ that require one. Thus, EHLORHUBARB was interpreted as a valid command.
+ This bug exists in every version of Exim that I still have, right back to
+ 0.12.
+
+PH/26 (n)wildlsearch lookups are documented as being done case-insensitively.
+ However, an attempt to turn on case-sensitivity in a regex key by
+ including (?-i) didn't work because the subject string was already
+ lowercased, and the effects were non-intuitive. It turns out that a
+ one-line patch can be used to allow (?-i) to work as expected.
+