Hello, at once I apologize for the English. I use the following configuration:
OS: Centos 6.8
ISPConfig
Roundcube 1.1.9 (not from yum, unpacked in / var/www/html)
Mailboxes on average 50-70GB
The problem is as follows we choose search in a subject, a body and in all folders. Some time everything works normally, but sooner or later ceases to work. That is he perfectly looks for on a letter subject in all folders, but it is worth complicating search having added criterion of search a letter body that he looks for some time then in the roundcube window the "expectation interval is exceeded..." window appears. Restart of such services as httpd, mysqld, dovecot and postfix does not fix a problem, but if completely to reboot the server, then search какоето time works. In logs of roundcube there is nothing.
The first question with what it is connected?
The second by means of what roundcube runs for search?
The third how to fix this problem?
The actual search is done by the mail server not Roundcube so your problem is most likely with the mail server. Try looking at the logs there and see if there is any information on what is happening.
There is nothing in the logs.
search in a body of the letter works only if to look for in the concrete folder and if there we graze no more than 4700 - 4900 pieces if more "the inquiry expectation interval is exceeded"