seeing following error message while trying to send email via postfix on Centos 7 while I can receive and download messages not seeing any errors
postfix/smtpd[24532]: connect from unknown[5.31.230.96]
postfix/smtpd[24532]: disconnect from unknown[5.31.230.96]
or
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]
or
postfix/smtpd[24371]: connect from unknown[unknown]
postfix/smtpd[24371]: lost connection after CONNECT from unknown[unknown]
postfix/smtpd[24371]: disconnect from unknown[unknown]
postfix/dovecot configuration as per article https://www.rosehosting.com/blog/mailserver-with-virtual-users-and-domains-using-postfix-and-dovecot-on-a-centos-6-vps/
Best Answer
This fix is for Redhat8 or 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