==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.9
- Deployed with iRedMail Easy or the downloadable installer? downloadable installer
- Linux/BSD distribution name and version: Debian 9
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL MariaDB (Remote Server)
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Hi,
Today I had install iredmail and have some trouble with the permission. The storage is connected as samba share under /media/storage. If I write an email and try to save it with roundcube or SOGo, I get a message like "Failed to store message "

UID and GID is vmail

ls -l /media
drwxr-xr-x 2 vmail vmail 0 Mar  3 10:09 storage

ls -l media/storage
drwxr-xr-x 2 vmail vmail 0 Mar  3 10:09 backup
drwxr-xr-x 2 vmail vmail 0 Mar  3 10:08 mlmmj
drwxr-xr-x 2 vmail vmail 0 Mar  3 10:09 mlmmj-archive
drwxr-xr-x 2 vmail vmail 0 Mar  3 10:08 public
drwxr-xr-x 2 vmail vmail 0 Mar  3 13:14 sieve
drwxr-xr-x 2 vmail vmail 0 Mar  3 13:15 vmail1

Mar  3 18:25:18 mail dovecot: imap-login: Login: user=<tobi@domain.de>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=3967, secured, session=<srkawzSDfNJ/AAAB>
Mar  3 18:25:18 mail dovecot: imap(tobi@domain.de): Error: rename(/media/storage/vmail1/domain.de/t/o/b/tobi-2019.03.03.12.55.51//Maildir/.Drafts/dovecot-uidlist.tmp, /media/storage/vmail1/domain.de/t/o/b/tobi-2019.03.03.12.55.51//Maildir/.Drafts/dovecot-uidlist) failed: Permission denied

Mar  3 18:25:18 mail dovecot: imap(tobi@domain.de): Panic: file maildir-save.c: line 774 (maildir_save_sync_index): assertion failed: (first_uid != 0)
Mar  3 18:25:18 mail dovecot: imap(tobi@domain.de): Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x95e92) [0x7f5a357ace92] -> /usr/lib/dovecot/libdovecot.so.0(+0x95f8d) [0x7f5a357acf8d] -> /usr/lib/dovecot/libdovecot.so.0(i_f+0x2a) [0x55fc7a3e1fea]
Mar  3 18:25:18 mail dovecot: imap(tobi@domain.de): Fatal: master: service(imap): child 3967 killed with signal 6 (core dumps disabled)

dovecot.conf

# User/group who owns the message files:
mail_uid = 2000
mail_gid = 2000

root@mail:~# id vmail
uid=2000(vmail) gid=2000(vmail) groups=2000(vmail)

What is wrong with my configuration?

Thanks a lot.
Tobi