Postfix / dovecot won’t work

My configuration of dovecot – postfix – postfixadmin won't work.

Since i'm pretty new to emails, i followed this tutorial

My server is an Ubuntu 13.04 server.
Email sending from localhost works as intended and mx records are setup correctly.

Here's the error in mail.err and when i try to connect to my mailbox with MS Outlook 2013

 Aug 31 06:00:15 NewWeb dovecot: imap(cappyt@xxxxx.it): Error: user cappyt@xxxxx.it: Initialization failed: Namespace '': mkdir(/home/vmail/xxxxx.it/cappyt) failed: Permission denied (euid=5000(vmail) egid=5000(vmail) missing +w perm: /home, dir owned by 0:0 mode=0755)
Aug 31 06:00:15 NewWeb dovecot: imap(cappyt@xxxxx.it): Error: Invalid user settings. Refer to server log for more information.

And here in mail.log

Aug 31 06:00:01 NewWeb postfix/pickup[8523]: 28C8481010: uid=107 from=<smmsp>
Aug 31 06:00:01 NewWeb postfix/cleanup[12949]: 28C8481010: message-id=<20130831040001.28C8481010@mail.xxxxx.it>
Aug 31 06:00:01 NewWeb postfix/qmgr[8524]: 28C8481010: from=<smmsp@mail.xxxxx.it>, size=709, nrcpt=1 (queue active)
Aug 31 06:00:01 NewWeb postfix/local[12953]: 28C8481010: to=<root@mail.xxxxx.it>, orig_to=<root>, relay=local, delay=0.02, delays=0.01/0.01/0/0, dsn=2.0.0, status=sent (delivered to command: procmail -a "$EXTENSION")
Aug 31 06:00:01 NewWeb postfix/qmgr[8524]: 28C8481010: removed
Aug 31 06:00:12 NewWeb dovecot: config: Warning: NOTE: You can get a new clean config file with: doveconf -n > dovecot-new.conf
Aug 31 06:00:12 NewWeb dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:102: add auth_ prefix to all settings inside auth {} and remove the auth {} section completely
Aug 31 06:00:12 NewWeb dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:103: userdb sql {} has been replaced by userdb { driver=sql }
Aug 31 06:00:12 NewWeb dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:106: passdb sql {} has been replaced by passdb { driver=sql }
Aug 31 06:00:12 NewWeb dovecot: auth-worker(12961): mysql(yy.yy.yy.yy): Connected to database postfix_mail
Aug 31 06:00:15 NewWeb dovecot: imap-login: Login: user=<cappyt@xxxxx.it>, method=PLAIN, rip=x.x.x.x, lip=yy.yy.yy.yy, mpid=12963, TLS, session=<yHREYDblxgCf/4PT>
Aug 31 06:00:15 NewWeb dovecot: imap(cappyt@xxxxx.it): Error: user cappyt@xxxxx.it: Initialization failed: Namespace '': mkdir(/home/vmail/xxxxx.it/cappyt) failed: Permission denied (euid=5000(vmail) egid=5000(vmail) missing +w perm: /home, dir owned by 0:0 mode=0755)
Aug 31 06:00:15 NewWeb dovecot: imap(cappyt@xxxxx.it): Error: Invalid user settings. Refer to server log for more information.
Aug 31 06:00:15 NewWeb postfix/smtpd[12964]: connect from ip-159-255-131-211.in-addr.ntrnet.it[x.x.x.x]
Aug 31 06:00:15 NewWeb postfix/smtpd[12964]: warning: ip-159-255-131-211.in-addr.ntrnet.it[x.x.x.x]: SASL LOGIN authentication failed: no mechanism available
Aug 31 06:00:15 NewWeb postfix/smtpd[12964]: lost connection after AUTH from ip-159-255-131-211.in-addr.ntrnet.it[x.x.x.x]
Aug 31 06:00:15 NewWeb postfix/smtpd[12964]: disconnect from ip-159-255-131-211.in-addr.ntrnet.it[x.x.x.x]

I really don't know where's the problem, since write permissions has been applied to /var/vmail to user vmail:vmail (5000:5000)

Also if other configuration is needed, ask in comments.