So, I'll now be a bit insisting, but could you now try with: mail_location = maildir:~/mails
Ok, will go try now.
If it works, this may prove useful in the future (for example, should you want make use of sieve or easily avoid to have >the control/index files taken into account for the quotas).
Ah yes, Sieve. That's going to be my next challenge. I have not tested it yet, but have been wondering if the various sieve directory settings (e.g. sieve_dir,sieve,sieve_global_dir etc. etc.) operate independently of the "general" Dovecot directory settings (e.g. mail_location, the home directory in user files etc.) ?
As a last step, you could then try to chroot again.
Only if someone can suggest why my original chroot config didn't work first, otherwise I'll just be breaking things again ;-)