在 Centos 7 上尝试通过 postfix 发送电子邮件时看到以下错误消息，而我可以接收和下载消息而没有看到任何错误
postfix/smtpd[24532]: connect from unknown[5.31.230.96]
postfix/smtpd[24532]: disconnect from unknown[5.31.230.96]
或者
postfix/smtpd[24366]: connect from unknown[5.31.230.96]
postfix/smtpd[24366]: warning: Wrapper-mode request dropped from unknown[5.31.230.96] for service submission. TLS context initial...our logs.
postfix/smtpd[24366]: disconnect from unknown[5.31.230.96]
postfix/smtpd[24366]: connect from unknown[5.31.230.96]
postfix/smtpd[24366]: warning: Wrapper-mode request dropped from unknown[5.31.230.96] for service submission. TLS context initial...our logs.
postfix/smtpd[24366]: disconnect from unknown[5.31.230.96]
postfix/smtpd[24369]: connect from unknown[5.31.183.32]
postfix/smtpd[24369]: lost connection after EHLO from unknown[5.31.183.32]
postfix/smtpd[24369]: disconnect from unknown[5.31.183.32]
或者
postfix/smtpd[24371]: connect from unknown[unknown]
postfix/smtpd[24371]: lost connection after CONNECT from unknown[unknown]
postfix/smtpd[24371]: disconnect from unknown[unknown]
按照文章中的 postfix/dovecot 配置https://www.rosehosting.com/blog/mailserver-with-virtual-users-and-domains-using-postfix-and-dovecot-on-a-centos-6-vps/
答案1
此修复程序适用于 Redhat8 或 Rocky Linux
/etc/postfix/main.cf
smtpd_sasl_auth_enable = yes
smtpd_sasl_application_name = smtpd
smtpd_relay_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
smtpd_sender_restrictions = reject_unknown_sender_domain