mail/exim: upgrade to 4.75
1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support,
there is now LDAP/TLS support, given sufficiently modern OpenLDAP
client libraries. The following global options have been added in
support of this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file,
ldap_cert_key, ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
2. The pipe transport now takes a boolean option, "freeze_signal",
default false. When true, if the external delivery command exits on
a signal then Exim will freeze the message in the queue, instead of
generating a bounce.
3. Log filenames may now use %M as an escape, instead of %D (still
available). The %M pattern expands to yyyymm, providing month-level
4. The $message_linecount variable is now updated for the maildir_tag
option, in the same way as $message_size, to reflect the real number
of lines, including any header additions or removals from transport.
5. When contacting a pool of SpamAssassin servers configured in
spamd_address, Exim now selects entries randomly, to better scale in
a cluster setup.
Full changelog and new stuff files:
Added two configurable knobs (based on ports/154956):
- CONFIG_FILE_PATH: location of the main configuration file
- ALT_CONFIG_PREFIX: prefix for alternative configuration files.
Feature safe: yes
Approved by: garga (mentor)