新问题，关于qmail+vpopmail.

littleicelee

redhat+qmail+vpopmail+qmailscaner，防毒用的是antivir,系统一直运行正常，最近忽然出现收信速度特别慢的情况，直到连接不上，telnet 本机ip地址的110端口，连接不上，重新启动mail服务，就没有问题，收发信都可以，过一会就又不可以了，看mailog.
May 31 10:31:09 ng qmail: 1085970669.022901 status: local 0/10 remote 19/20
May 31 10:31:09 ng qmail: 1085970669.023392 starting delivery 153: msg 362631 to remote znwb@znwb.com
May 31 10:31:09 ng qmail: 1085970669.023447 status: local 0/10 remote 20/20
May 31 10:31:09 ng qmail: 1085970669.300445 delivery 153: deferral: Sorry,_I_wasn't_able_to_establish_an_SMTP_connection._(#4.4.1)/