Search Mail Log Error - Perl execution failed

This feature has not worked on our primary server for a long time, possibly never. When performing a mail log search from any domain, the search appears to run for a minute or so and then times out with an error. My initial assumption was that the search was taking too long because the mail logs were too large. So, I switched the logrotate configuration from monthly to weekly, and they are now about 25% of their former size.

Uncompressed, our monthly logs were about 1 GB, so the weekly logs are about 200-300 MB each. Logrotate automatically compresses them down to about 25 MB using gzip. If I search the older compressed logs manually with zgrep, it takes about 20 seconds to get the results.

I later realized that this may all be moot, since the logs are indexed based on the configuration setting for "Number of days to keep processed mail logs" (under Advanced Options), which was set to the default of 30 days. I noticed that my procmail.cache.pag file is 2 GB, and my procmail.cache.dir is 250 MB. I don't know if these are normal sizes or too large, but I just changed the setting to only 14 days, so I assume they should drop to half the size. How do I cause them to be reprocessed/updated so I can test if this resolves the issue?

BTW, I also noticed a file named procmail.times, which hasn't been updated since 2013. Is that a problem, or should that file be deleted?

Thanks, Alan