系统环境
iredmail ：0.9.7
iRedAdmin-Pro-2.8.0
数据库：mysql
操作系统：centos6.9

在dovet日志中发现如下错误

Nov 20 12:01:55 lda(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 20 12:03:55 lda(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 20 12:07:58 lda(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 20 12:12:01 lda(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 20 12:16:05 lda(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 21 09:33:54 pop3(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index
Nov 21 10:04:13 pop3(hrfw@xxx.com.cn): Error: Timeout (120s) while waiting for shared lock for index file /var/vmail/vmail1/xxx.com.cn/h/r/f/hrfw-2014.08.15.10.41.28//Maildir/dovecot.index

hrfw@xxx.com.cn 账号无法正常接收\发送邮件,之前从来没有过这个问题,请指教.