环境：exchange 2010 sp3+exchange 2013 cu15
问题服务器：exchange 2013 (发布到公网)
问题表现：IIS连接数每天不断在增加，连接长时间不断开

利用APPCMD.EXE导出IIS实时连接情况，看到大量类似如下这样的连接（user和deivceid我替换了真实的），每个连接的时间长度不等（有的连接自上次应用池回收以来就没有断开过）。
一个设备多则200多条，少则几十条，安卓和iphone都有。
请问这种问题是由于服务器IIS设置不正确导致的吗？

/Microsoft-Server-ActiveSync?Cmd=Ping&User=username@domain.com&DeviceId=android&DeviceType=Android,
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