Hi
I need to check my mailboxes for errors.
My imapd has permanent errors, it periodically crashes. I think that the problem will be with some errors which was created when I converted my previous maildirs to mailboxes.

It is possible to check the integrity of these mailboxes with some command or script??

Thanks in advance for your responses

Have some results.
Maybe it helps to someone who experiences the same problem with imapd on Slackware.
The MUA is Thunderbird (previous-v.3.1.10 now-v.5.0) - finally it was the source of the problems. (Note I am not the administrator of those PCs, we use SSL)

Since my users have lots of huge mailboxes (1-4 GB) we was synchronize those mailboxes on Thunderbird. (It downloads the boxes to the local PC)
Somehow the Thunderbird gets into zombie state on the client desktops (MS) when the Thunderbird was closed. It stays in the process list and generate a huge traffic. I don't know, maybe a virus or corrupted Thunderbird (corrupted local mailbox??) ... but finally the complete uninstall of Thunderbird (also with deletion of the garbage left behind the installer - the downloaded mboxes, profiles, cache) solved the problem.

I keep the thread updated with the results of the long-term testing. (Note the actual state was - every-day crash of imapd)

Well, finally the errors are discovered. There were format errors in the mailbox. Lots of messages does contain special characters in the message header which should not be there.
Example:
Several of messages in lots of mailboxes contains the HEX 0x0d character. This caused the imapd in Slackware crash sometimes with segfault. I still try to reproduce the segfault state but I don't know which operations on this mails caused the segfault.
I noted that the segfault state was preceded by Use Hang logs in imap. After some of these hangs the crash happend.

The error was discovered with help of Dovecot. I changed the imap daemon in Slackware and I get more accurate error messages about this crashes. In one moment Dovecot showed the message (with one mailbox) that it cannot open the mailbox because it is not a proper mbox file. After this I examined this mbox file. I cut the mbox into separated message files.
This produced header files and message body files. First I did not noticed the 0x0d character in the From line. But when I discovered it I deleted the character, rebuilt the mbox and I could access the mailbox again.
I expected that this character get into the mbox file by mistake. But finally I found out that in another mbox there was plenty of errors like this. All the messages was sent by blackberry smartphone.