[Dovecot] Auto rebuild indexes?

[Emilio]

I have another easy question for you, Timo:

When cache files were deleted because some corruption, is there a way to
regenerate all cache files in all accounts?

I'm talking about 300GB of mails distributed in 40 accounts using Maildir; when
all users tried to access their mailboxes with their MUA at the same time,
dovecot produced a high load average in the server making it unusable, so would
be useful a function that instructs dovecot to check all cache files and
regenerate the missing or corrupted ones while no user is accesing its mailbox.
Is that possible?