==== Required information ====
- iRedMail version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Linux/BSD distribution name and version:
- Related log if you're reporting an issue:
======== Required information ====
- iRedMail version:  0.9.0
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  LDAP (slapd 2.4.39)
- Web server (Apache or Nginx): Apache/2.2.15
- Linux/BSD distribution name and version: CentOS 6.6
- Related log if you're reporting an issue: dovecot log (version 2.1.17)
====

I just did a brand new install on a completely fresh VPS of CentOS 6.6 x86_64. After rebooting as requested, I cannot login using the postmaster account. The error message is "connection to storage server failed" on the Roundcube login screen. Looking at the dovecot log shows this:

May 09 20:38:13 imap(postmaster@example.org): Error: chdir(/var/mail/vmail1/example.org/p/o/s/postmaster-2015.05.09.16.35.00//) failed: Permission denied (euid=2000(vmail) egid=2000(vmail) missing +x perm: /var/mail, dir owned by 0:12 mode=0700)
May 09 20:38:13 imap(postmaster@example.org): Error: chdir(/var/mail/vmail1/example.org/p/o/s/postmaster-2015.05.09.16.35.00/) failed: Permission denied
May 09 20:38:13 imap(postmaster@example.org): Error: user postmaster@example.org: Initialization failed: Namespace '': stat(/var/mail/vmail1/example.org/p/o/s/postmaster-2015.05.09.16.35.00//Maildir) failed: Permission denied (euid=2000(vmail) egid=2000(vmail) missing +x perm: /var/mail, dir owned by 0:12 mode=0700)

On CentOS, /var/mail is a link to /var/spool/mail which is owned by root:mail.

So I changed the owner of /var/spool/mail to vmail and it logged in OK. I am not sure if that hoses other permissions, so I thought that I would report it. I have not tested anything else yet.