diff --git a/management/daemon.py b/management/daemon.py
index 6de0a59a..bf3c9134 100755
--- a/management/daemon.py
+++ b/management/daemon.py
@@ -6,17 +6,11 @@ from functools import wraps
 
 from flask import Flask, request, render_template, abort, Response, send_from_directory
 
-import auth, utils
+import auth, utils, multiprocessing.pool
 from mailconfig import get_mail_users, get_mail_users_ex, get_admins, add_mail_user, set_mail_password, remove_mail_user
 from mailconfig import get_mail_user_privileges, add_remove_mail_user_privilege
 from mailconfig import get_mail_aliases, get_mail_aliases_ex, get_mail_domains, add_mail_alias, remove_mail_alias
 
-# Create a worker pool for the status checks. The pool should
-# live across http requests so we don't baloon the system with
-# processes.
-import multiprocessing.pool
-pool = multiprocessing.pool.Pool(processes=5)
-
 env = utils.load_environment()
 
 auth_service = auth.KeyAuthService()
@@ -436,7 +430,10 @@ def system_status():
 		def print_line(self, message, monospace=False):
 			self.items[-1]["extra"].append({ "text": message, "monospace": monospace })
 	output = WebOutput()
+	# Create a temporary pool of processes for the status checks
+	pool = multiprocessing.pool.Pool(processes=5)
 	run_checks(False, env, output, pool)
+	pool.terminate()
 	return json_response(output.items)
 
 @app.route('/system/updates')
diff --git a/management/mailconfig.py b/management/mailconfig.py
index d9ffdf65..d044c1ab 100755
--- a/management/mailconfig.py
+++ b/management/mailconfig.py
@@ -137,19 +137,20 @@ def get_mail_users_ex(env, with_archived=False, with_slow_info=False):
 	if with_archived:
 		root = os.path.join(env['STORAGE_ROOT'], 'mail/mailboxes')
 		for domain in os.listdir(root):
-			for user in os.listdir(os.path.join(root, domain)):
-				email = user + "@" + domain
-				mbox = os.path.join(root, domain, user)
-				if email in active_accounts: continue
-				user = {
-					"email": email,
-					"privileges": "",
-					"status": "inactive",
-					"mailbox": mbox,
-				}
-				users.append(user)
-				if with_slow_info:
-					user["mailbox_size"] = utils.du(mbox)
+			if os.path.isdir(os.path.join(root, domain)):
+				for user in os.listdir(os.path.join(root, domain)):
+					email = user + "@" + domain
+					mbox = os.path.join(root, domain, user)
+					if email in active_accounts: continue
+					user = {
+						"email": email,
+						"privileges": "",
+						"status": "inactive",
+						"mailbox": mbox,
+					}
+					users.append(user)
+					if with_slow_info:
+						user["mailbox_size"] = utils.du(mbox)
 
 	# Group by domain.
 	domains = { }
diff --git a/setup/preflight.sh b/setup/preflight.sh
index 26df3ed1..e854249e 100644
--- a/setup/preflight.sh
+++ b/setup/preflight.sh
@@ -33,3 +33,10 @@ if [ ! -d /vagrant ]; then
 	exit
 fi
 fi
+
+# Check that tempfs is mounted with exec
+MOUNTED_TMP_AS_NO_EXEC=$(grep "/tmp.*noexec" /proc/mounts)
+if [ -n "$MOUNTED_TMP_AS_NO_EXEC" ]; then
+	echo "Mail-in-a-Box has to have exec rights on /tmp, please mount /tmp with exec"
+	exit
+fi
diff --git a/setup/start.sh b/setup/start.sh
index ab6d3055..3a93ac22 100755
--- a/setup/start.sh
+++ b/setup/start.sh
@@ -5,7 +5,8 @@
 source setup/functions.sh # load our functions
 
 # Check system setup: Are we running as root on Ubuntu 14.04 on a
-# machine with enough memory? If not, this shows an error and exits.
+# machine with enough memory? Is /tmp mounted with exec.
+# If not, this shows an error and exits.
 source setup/preflight.sh
 
 # Ensure Python reads/writes files in UTF-8. If the machine