Corrupted index cache after migrating from maildir to mdbox

Timo Sirainen tss at
Wed Oct 15 03:05:57 UTC 2014

On 27 Sep 2014, at 17:48, Tim <tim at> wrote:

> unfortunately I'm getting the following two kinds of error messages for
> all mail boxes in my mail.log:
> Error: Corrupted index cache file
> /home/vmail/%domain/%user/mdbox/mailboxes/%maildir/dbox-Mails/dovecot.index.cache:
> Broken virtual size for mail UID 2564
> and:
> Error: read(/home/vmail/%domain/%user/mdbox/storage/m.108
> ): FETCH BODY[] for mailbox %maildir UID 2564 got too little data: 2417
> vs 6319

If that happens to all the mails, something went wrong. Did you maybe use zlib plugin while writing the messages (compressed), but now you're trying to read the mails without zlib plugin?

The error messages may be somewhat confusing. The problem isn't dovecot.index.cache file, but that the message sizes in the m.* files don't match the contents. There's no easy way to fix those, because they should just about never be wrong.

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