张工您好,我装的iredmail服务器之前正常使用,突然无法收发邮件,日志贴出来 麻烦您帮我看下什么原因
os:centos 7.6
mysql
iredmail 0.9.9

Oct 30 11:14:14 mx2019 postfix/postscreen[23310]: CONNECT from [49.84.165.89]:64707 to [172.16.200.93]:25
Oct 30 11:14:14 mx2019 postfix/submission/smtpd[31301]: connect from mx2019.steelhome.cn[127.0.0.1]
Oct 30 11:14:14 mx2019 postfix/submission/smtpd[31301]: Anonymous TLS connection established from mx2019.steelhome.cn[127.0.0.1]: TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)
Oct 30 11:14:14 mx2019 postfix/submission/smtpd[31301]: 472tpZ5PPRz5HLPJ: client=mx2019.steelhome.cn[127.0.0.1], sasl_method=LOGIN, sasl_username=chenc@steelhome.cn
Oct 30 11:14:14 mx2019 postfix/cleanup[30866]: 472tpZ5PPRz5HLPJ: message-id=<ad22ed87997b9649ac263d5826dea09c@steelhome.cn>
Oct 30 11:14:14 mx2019 roundcube: <buhilas8> User chenc@steelhome.cn [172.16.130.58]; Message for wuwx@steelhome.cn; 250: 2.0.0 Ok: queued as 472tpZ5PPRz5HLPJ
Oct 30 11:14:14 mx2019 postfix/submission/smtpd[31301]: disconnect from mx2019.steelhome.cn[127.0.0.1]
Oct 30 11:14:15 mx2019 postfix/postscreen[23310]: DNSBL rank 5 for [110.83.132.226]:53892
Oct 30 11:14:15 mx2019 postfix/postscreen[23310]: DISCONNECT [110.83.132.226]:53892
Oct 30 11:14:15 mx2019 postfix/postscreen[23310]: CONNECT from [222.246.43.203]:4912 to [172.16.200.93]:25
Oct 30 11:14:16 mx2019 postfix/dnsblog[30776]: addr 222.246.43.203 listed by domain zen.spamhaus.org as 127.0.0.11
Oct 30 11:14:16 mx2019 postfix/dnsblog[30776]: addr 222.246.43.203 listed by domain zen.spamhaus.org as 127.0.0.3
Oct 30 11:14:16 mx2019 postfix/dnsblog[30776]: addr 222.246.43.203 listed by domain zen.spamhaus.org as 127.0.0.4
Oct 30 11:14:16 mx2019 postfix/dnsblog[30755]: addr 222.246.43.203 listed by domain b.barracudacentral.org as 127.0.0.2
Oct 30 11:14:16 mx2019 postfix/postscreen[23310]: HANGUP after 5.1 from [49.84.165.89]:64573 in tests before SMTP handshake
Oct 30 11:14:16 mx2019 postfix/postscreen[23310]: DISCONNECT [49.84.165.89]:64573