==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.8.7
- Deployed with iRedMail Easy or the downloadable installer?  The downloadable installer
- Linux/BSD distribution name and version: CentOS release 5.2 (Final)
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Apache
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Mr.Zhang

My mail server dovecot restart failed and the log as follow.
Mar 01 08:19:07 dovecot: Fatal: setrlimit(RLIMIT_DATA, 256): Operation not permitted
Mar 01 08:19:07 dovecot: Error: child 15908 (auth) returned error 89 (Fatal failure)
Mar 01 08:19:07 dovecot: Fatal: Auth process died too early - shutting down
Mar 01 08:24:41 dovecot: Info: Dovecot v1.2.16 starting up (core dumps disabled)
Mar 01 08:24:41 dovecot: Fatal: setrlimit(RLIMIT_DATA, 256): Operation not permitted
Mar 01 08:24:41 dovecot: Error: child 16202 (auth) returned error 89 (Fatal failure)
Mar 01 08:24:41 dovecot: Fatal: Auth process died too early - shutting down

/var/www/roundcubemail/logs/errors
[26-Feb-2020 17:02:43 +0800]: IMAP Error: Login failed for luoli0903@xxx.com.cn from 192.168.xxx.66. Empty startup greeting (127.0.0.1:143) in /usr/local/wwww/roundcubemail-0.9.4/program/lib/Roundcube/rcube_imap.php on line 184 (GET /?_task=mail&_mbox=INBOX&_folderlist=1&_list=1&_quota=1&_action=refresh&_remote=1&_unlock=loading1582707699578&_=1582707699579)

Thanks.