Allow to enable debug flag for javamail

modules/joex/src/main/resources/reference.conf

@@ -31,6 +31,12 @@ docspell.joex {
     password = ""
   }
 
+  # Enable or disable debugging for e-mail related functionality. This
+  # applies to both sending and receiving mails. For security reasons
+  # logging is not very extensive on authentication failures. Setting
+  # this to true, results in a lot of data printed to stdout.
+  mail-debug = false
+
   send-mail {
     # This is used as the List-Id e-mail header when mails are sent
     # from docspell to its users (example: for notification mails). It

modules/joex/src/main/scala/docspell/joex/Config.scala

@@ -22,7 +22,8 @@ case class Config(
     textAnalysis: TextAnalysisConfig,
     convert: ConvertConfig,
     sendMail: MailSendConfig,
-    files: Files
+    files: Files,
+    mailDebug: Boolean
 )
 
 object Config {

modules/joex/src/main/scala/docspell/joex/JoexAppImpl.scala

@@ -70,7 +70,8 @@ object JoexAppImpl {
       nodeOps <- ONode(store)
       joex    <- OJoex(client, store)
       upload  <- OUpload(store, queue, cfg.files, joex)
-      javaEmil = JavaMailEmil(blocker)
+      javaEmil =
+        JavaMailEmil(blocker, Settings.defaultSettings.copy(debug = cfg.mailDebug))
       sch <- SchedulerBuilder(cfg.scheduler, blocker, store)
         .withQueue(queue)
         .withTask(