dovecot: migrated config to 2.4 + config splitting

data/conf/dovecot/conf.d/60-sieve-pipeline.conf

@@ -0,0 +1,78 @@
+# /etc/dovecot/conf.d/60-sieve-pipeline.conf
+# Complete Sieve pipeline: personal/global scripts, plugins, limits, training.
+
+# Personal scripts
+sieve_script personal {
+  driver = file
+  path = ~/sieve
+  active_path = ~/.dovecot.sieve
+}
+
+# Global before/after (file and dict)
+sieve_script before {
+  driver = file
+  path = /var/vmail/sieve/global_sieve_before.sieve
+}
+sieve_script before2 {
+  driver = dict
+  name = active
+  dict proxy {
+    name = sieve_before
+    sieve_script_bin_path = /var/vmail/sieve_before_bindir
+  }
+}
+sieve_script after {
+  driver = file
+  path = /var/vmail/sieve/global_sieve_after.sieve
+}
+sieve_script after2 {
+  driver = dict
+  name = active
+  dict proxy {
+    name = sieve_after
+    sieve_script_bin_path = /var/vmail/sieve_after_bindir
+  }
+}
+
+# Plugins and behavior
+sieve_plugins = sieve_imapsieve sieve_extprograms
+sieve_vacation_send_from_recipient = yes
+sieve_redirect_envelope_from = recipient
+
+# IMAPSieve training
+imapsieve_from Junk {
+  sieve_script ham {
+    type = before
+    cause = copy
+    path = /usr/lib/dovecot/sieve/report-ham.sieve
+  }
+}
+mailbox Junk {
+  sieve_script spam {
+    type = before
+    cause = copy
+    path = /usr/lib/dovecot/sieve/report-spam.sieve
+  }
+}
+
+# Extprograms and extensions
+sieve_pipe_bin_dir = /usr/lib/dovecot/sieve
+sieve_plugins {
+  sieve_extprograms = yes
+}
+sieve_global_extensions {
+  vnd.dovecot.pipe = yes
+  vnd.dovecot.execute = yes
+}
+
+# Limits and duplicate handling
+sieve_max_script_size = 1M
+sieve_max_redirects = 100
+sieve_max_actions = 101
+sieve_quota_script_count = 0
+sieve_quota_storage_size = 0
+sieve_vacation_min_period = 5s
+sieve_vacation_max_period = 365d
+sieve_vacation_default_period = 60s
+sieve_duplicate_default_period = 1m
+sieve_duplicate_max_period = 7d