[Dovecot] Disable maildir indexing and dovecot-uidlist on LMTP/LDA delivery

[Joseph Tam]

On Thu, 3 Apr 2014, Jouko Nikula wrote:

> I now used:
>
>  mail_location = maildir:~/mail:INDEX=MEMORY:CONTROL=/var/mail/%d/ctrl/%u
>
> and for sieve:
>
> plugin {
>  sieve = /var/mail/%d/ctrl/%u/dovecot.sieve
>  sieve_dir = /var/mail/%d/ctrl/%u/
> }
>
> I also have two dovecot instances. One is responsible for imap/pop3 and other
> is responsible for sasl and and lmtp. The latter uses configuration above and
> the former differs on the mail location so that it does not have the
> INDEX=MEMORY setting:
>
> mail_location = maildir:~/mail:CONTROL=/var/mail/%d/ctrl/%u
>
> Do you see problems in this setup?

No, but I don't use sieve (nor INDEX=MEMORY for that matter), so my
knowledge is limited here.

> My understanding is that now I'm wasting little bit CPU on creating
> indices for new mail, but I nevertheless have working and stored
> indices on the dovecot's imap instance.

I/O is more precious than CPU, and that's what indices tries to conserve.
I don't know how much performance degradation append operations (i.e. new
mail) has on index updates, but it's probably proportional to mailbox
size.

If your mailboxes are small, it's probably negligible.

>> However, I would look at the cause of the "insufficient privileges":
>> it is a symptom of something that could lead to other problems.
>
> The cause is that I have not given lmtp read access to mail/home dir.
> :-) So this is intentional.

That is bizarre -- I can't think of how you can profit from denying read
access to indices, but allow write access, and also allow read access
to the mailboxes.

Joseph Tam <jtam.home at gmail.com>