[Dovecot] Intermittent "cannot update mailbox" problems w/ postfix & dovecot

[John Reddy]

I never did locate the root cause of the problem I was experiencing.
The problem seems to have been fixed by switching to the Dovecot LDA
(deliver) by putting in the /etc/postfix/main.cf:
mailbox_command = /usr/local/libexec/dovecot/deliver -c
/usr/local/etc/dovecot.conf -f "$SENDER"

I brought this up on the postfix mailing list as well.  According to
Wietse Venema:
>
>
> We're looking at this code fragment:
>
>
>     /*
>       * Open an existing file.
>       */
>      if ((fp = vstream_fopen(path, flags & ~(O_CREAT | O_EXCL), 0)) == 0) {
>          saved_errno = errno;
>          vstring_sprintf(why, "cannot open file: %m");
>          errno = saved_errno;
>          return (0);
>      }
>  Since the file already exists, Postfix attempts to open it with
>  the recipient's uid/gid privileges.
...
>
>
> > Does anyone have any advice on how I might get better details about
> > why postfix is having trouble accessing the file?
>  "Permission denied" is what the kernel says in response to an
>  open(2) or write(2) request. Postfix just delivers the bad news.
>

Wietse is the one who suggested switching to the Dovecot LDA, and it
does seem to be working out well.

-John



On 12/22/06, Timo Sirainen <tss at iki.fi> wrote:
> On 8.12.2006, at 23.30, John Reddy wrote:
>
> > Dec  7 09:42:05 solaris-host local[18332]: [ID 197553 mail.info]
> > D35C3445C: to=<bubba at solaris-host.sample.com>, relay=local,
> > delay=0.17, delays=0.09/0/0/0.08, dsn=5.2.0, status=bounced (cannot
> > update mailbox /var/mail/bubba for user bubba. cannot open file:
> > Permission denied)
>
> I'd guess you're solved this already somehow, but to me it looks like
> a Postfix configuration problem. Maybe you've configured Postfix to
> use different UID for a user than for Dovecot.
>