Hi everyone,
we just upgraded our mail server from Debian 8 to Debian 9, so our dovecot packages just got upgraded from version 2.2.13 to 2.2.17.
Now we have a lot of errors in our dovecot.log about permission denied (our Mailboxes are on NFS remote server since years without problems) like these:
Jul 13 12:39:23 Error: imap(XXXXXXXXX): open(/mnt/mail-storage/XXXXXXXXX/Maildir/cur/1594378191.M653755P26498.ganimede,S=12716,W=12984:2,S) failed: Permission denied (euid=501(vmail) egid=501(vmail) missing +r perm: /mnt/mail-storage/XXXXXXXXX/Maildir/cur/1594378191.M653755P26498.ganimede,S=12716,W=12984:2,S stat(/mnt/mail-storage/XXXXXXXXX/Maildir/cur/1594378191.M653755P26498.ganimede,S=12716,W=12984:2,S) failed: Permission denied)
For some user this is not a problem, for some other user this blocks their mail client (Thunderbird).
We use vmail user for running Dovecot and I can't find a permission problem on the path indicated by the mail error, user vmail can read and write and uid and gid seems to be correct.
Permissions on
/mnt/mail-storage
was
drwx------ 94 vmail vmail 4096 ago 29 2019 mail-storage
I just changed to
drwxr-xr-x 94 root root 4096 ago 29 2019 mail-storage
but nothing has changed.
Every directory and sub-dir under
/mnt/mail-storage
is assigned to vmail:vmail with
drwx------
permission set.
If try to stat on
/mnt/mail-storage/XXXXXXXXX/Maildir/cur/1594378191.M653755P26498.ganimede,S=12716,W=12984:2,S
I get permission denied.
We use LMTP and Postfix to deliver mail to mailbox.
mail_debug=yes already enabled; mail_fsync is set to never (should I change to always?).
Please could you give us help on the matter as I don't know where to look further.
Thanks
Claudio