Configure Dovecot’s autocomplete plugin.

Adds/subscribes Drafts, Sent, Junk, Trash and Archive mailboxes.

roles/mailserver/files/etc_dovecot_conf.d_20-imap.conf

   #mail_max_userip_connections = 10
 
   # Space separated list of plugins to load (default is global mail_plugins).
-  mail_plugins = $mail_plugins antispam fts fts_solr
+  mail_plugins = $mail_plugins antispam fts fts_solr autocreate
 
   # IMAP logout format string:
   #  %i - total number of bytes read from client

roles/mailserver/files/etc_dovecot_conf.d_90-plugin.conf

   # FTS (full text search with Solr)
   fts = solr
   fts_solr = break-imap-search url=http://localhost:8080/solr/
+  
+  # Autocreate (specify mailboxes that must always exist for all users)
+  autocreate = Drafts
+  autocreate2 = Sent
+  autocreate3 = Junk
+  autocreate4 = Trash
+  autocreate5 = Archive
+  autosubscribe = Drafts
+  autosubscribe2 = Sent
+  autosubscribe3 = Junk
+  autosubscribe4 = Trash
+  autosubscribe5 = Archive
 }