======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version: Debian 8
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? NO
====

Hello,

I had an issue with mobile devices syncing to SOGo's exchange service. It would drain the battery insanely fast.

The reason for this was the Heartbeat timeout of SOGo which is set to 10 seconds by default. After those 10 seconds, the mobile device has to reestablish the connection to the SOGo server.

I suggest setting timeouts way higher to prevent this.

In

/etc/sogo/sogo.conf

add the lines:

    SOGoMaximumPingInterval = 600;                                                                                                     
    SOGoMaximumSyncInterval = 600;                                                                                                     
    SOGoInternalSyncInterval = 30;  

Which raises the heartbeat timeout to 10 minutes.

Also, do the same for the proxy settings:

In

/etc/apache2/conf-available/SOGo.conf

I adjusted the values to:

ProxyPass /Microsoft-Server-ActiveSync \                                                                                               
 http://127.0.0.1:20000/SOGo/Microsoft-Server-ActiveSync \                                                                             
 retry=60 connectiontimeout=60 timeout=660

Especially have a look at this:
ActiveSync Tuning

Kind regards,
Adrian