add attachment saving script which isn't perfect yet but does its job

astroid/config

@@ -65,7 +65,7 @@
         "interval": "240"
     },
     "attachment": {
-        "external_open_cmd": "xdg-open"
+        "external_open_cmd": "/home/max/.config/astroid/scripts/attachment-saver.sh"
     },
     "thread_view": {
         "open_html_part_external": "false",

astroid/scripts/attachment-saver.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+#
+# based on https://github.com/astroidmail/astroid/issues/339#issuecomment-300491869
+
+cachedir=~/.cache/astroid-attachments
+attachment=$(echo $1 | sed "s#.*astroid/##")
+
+touch $cachedir/token.$attachment
+
+if [ ! -e ${cachedir} ]; then
+  mkdir -p ${cachedir}
+fi
+
+mv $1 ~/.cache/astroid-attachments/
+
+inotifywait -e close "$1" &
+ip=$!
+
+# open file (you can replace this with xdg-open)
+xdg-open "$cachedir/$attachment"
+
+while inotifywait -r -e close $cachedir/$attachment; do rm $cachedir/token.$attachment || rm $cachedir/$attachment; done