The index is not in the allowed range.

[alejandro.picado]

Thanks in advance for reading my post.
The problem's next:
I have certain accounts whose have about 200-300GB of mailbox and usually gets the error "The index is not in the allowed range" as a pop-up when they try to search a message from let's say, 3 or 4 years ago and for example, if the user do the search in the morning and gets the error and then do the search again hours later it shows correctly.
How can i do for get rid of these error? is related of some kind of cache?
Thanks.

Server: Physic.
Zimbra: 8.8.15 NE
RAM: 64 GB. DDR4 2666MHz
CPU: 1 socket, 4 cores 4.0 Ghz (top)
Opt volume: 10 TB