Incoming mail is not received in a server with Plesk: System error .qmail: Permission denied

Symptoms

• Incoming mail is not received after the manual migration of IMAP folders on a Plesk server;

• On accessing a mailbox the following error message can be found in /var/log/maillog:

  CONFIG_TEXT: cp postfix-local[18509]: postfix-local: from=johdoe@example.tld, to=janedoe@example.com, dirname=/var/qmail/mailnames
  cp postfix-local[18509]: System error .qmail: Permission denied
  cp postfix-local[18509]: Wrong permissions for .qmail

• In case Dovecot is installed the error in the /var/log/maillog file might look as follow:

  CONFIG_TEXT: dovecot: service=lda, user=johndoe@example.com, ip=[]. msgid=cec371129278c2a4bda8b4a7c748ee5b@example.com: save failed to INBOX: Mailbox INBOX: open(/var/qmail/mailnames/example.com/plesktest/Maildir/tmp/1540412707.M610145P50915.example.com) failed: Permission denied \

• The following warnings are shown in /var/log/audit/audit.log:

  CONFIG_TEXT: type=AVC msg=audit(1491845234.234:481226): avc: denied { getattr } for pid=2200 comm="postfix-local" path="/var/qmail/mailnames/example.com/joe/.qmail" dev="dm-0" ino=1912673223 scontext=system_u:system_r:postfix_pipe_t:s0 tcontext=unconfined_u:object_r:var_t:s0 tclass=file

• Deferred messages can be viewed in postfix mail queue:

  # postqueue -p

• Mail is delivered if SELinux is switched to permissive mode;

Cause

Files in the IMAP directory have incorrect SELinux context.

Resolution

1. Connect to the server via SSH.

2. Restore the default SELinux context for the /var/qmail/mailnames directory by executing the commands below one by one:

   # restorecon -R -v /var/qmail/mailnames/
   # restorecon /usr/libexec/postfix/plesk_saslauthd
   # restorecon -R /usr/lib64/plesk-9.0/
   # restorecon -R /var/lib/plesk/mail
   # restorecon -R /var/spool/postfix

3. In case the issue persists, reinstall psa-selinux package using the command below:

   # yum reinstall psa-selinux