Network service has occured during replying

[leencenters]

My zimbra 8.6 ,OS Redhat:6.5
Sometimes and randomly when im replying to email from outside my network , there is an error "Network service has an occured"

zmprov gacf |grep -i zimbraHttpDosFilter
zimbraHttpDosFilterDelayMillis: 0
zimbraHttpDosFilterMaxRequestsPerSec: 100

zmprov gacf |grep -i InvalidLoginFilter

zimbraInvalidLoginFilterDelayInMinBetwnReqBeforeReinstating: 15
zimbraInvalidLoginFilterMaxFailedLogin: 0
zimbraInvalidLoginFilterMaxSizeOfFailedIpDb: 7000
zimbraInvalidLoginFilterReinstateIpTaskIntervalInMin: 5

anyone suggest how can fix the problem??

[tonster]

What do the logs tell you?

Sent from my SM-G950U using Tapatalk

[leencenters]

it seem No error

[leencenters]

Which file can i check??

[tonster]

Which file can i check??

https://wiki.zimbra.com/wiki/Log_Files

[leencenters]

i didnt find any error
just i found error related to index

[leencenters]

just this error not related to the main problem

[tonster]

just this error not related to the main problem

The indexing stuff is really not an error. It can't index some headers, so that is normal activity. You could also try looking in zmmailboxd.out. You don't see any stacktraces or anything when this happens?

[leencenters]

I found many repeated error like in the attachment files

[leencenters]

another print screen