Allow files in /home/user-data/mail/mailboxes

management/mailconfig.py

@@ -137,6 +137,7 @@ 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):
+			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)