==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version: Ubuntu 14.04 x64
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- Related log if you're reporting an issue:
====

I checked my logwatch email today and notice the below:

  499 (undefined)
       /Microsoft-Server-ActiveSync?Cmd=Sync&Devi ... ceId=xxxxxxxxxx: 56 Time(s)

Where xxxxxxxxx is my Blackberry Z10 PIN. Is there any incorrect setting that leads to the above mentioned error?

The full httpd section is right below for your information:

--------------------- httpd Begin ------------------------

Connection attempts using mod_proxy:
    111.248.116.136 -> 163mx02.mxmail.netease.com:25: 1 Time(s)
    111.248.63.213 -> 163mx02.mxmail.netease.com:25: 1 Time(s)
    222.186.34.194 -> www.google.com:443: 8 Time(s)

A total of 3 sites probed the server
    109.123.101.28
    169.50.3.171
    198.20.69.74

Requests with error response codes
    400 Bad Request
       www.google.com:443: 8 Time(s)
       null: 7 Time(s)
       163mx02.mxmail.netease.com:25: 2 Time(s)
   
    404 Not Found
       /favicon.ico: 3 Time(s)
       /admin/config.php: 2 Time(s)
       /xmlrpc.php: 2 Time(s)
       //cgi-bin/webcm?getpage=../html/menus/menu ... /voip.cfg%20%26: 1 Time(s)
       /myadmin/scripts/setup.php: 1 Time(s)
       /phpMyAdmin/scripts/setup.php: 1 Time(s)
       /pma/scripts/setup.php: 1 Time(s)
       /sitemap.xml: 1 Time(s)
    499 (undefined)
       /Microsoft-Server-ActiveSync?Cmd=Sync&Devi ... ceId=xxxxxxxxxx: 56 Time(s)
       
---------------------- httpd End -------------------------