Hello. I am trying to find an error for the lost connection error. I tried several different sources but don't seem to make any progress. Thank you for pointing me into the right direction.
Jan 12 14:01:02 home postfix/submission/smtpd[7046]: connect from unknown[10.5.2.1] Jan 12 14:01:02 home postfix/submission/smtpd[7046]: discarding EHLO keywords: CHUNKING Jan 12 14:01:02 home postfix/submission/smtpd[7046]: Anonymous TLS connection established from unknown[10.5.2.1]: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits) Jan 12 14:01:02 home postfix/submission/smtpd[7046]: lost connection after STARTTLS from unknown[10.5.2.1] Jan 12 14:01:02 home postfix/submission/smtpd[7046]: disconnect from unknown[10.5.2.1] ehlo=1 starttls=1 commands=2 Some related config info: I run my server with letsencrypt certificates. - certbot certonly -a apache --agree-tos --staple-ocsp --email <name><domain> -d <FQDN> - smtpd_tls_cert_file, smtpd_tls_key_file and ssl_cert, - Dovevot: ssl_key and ssl_cert are set service auth { unix_listener /var/spool/postfix/private/auth { mode = 0600 user = postfix group = postfix } } - submission inet n - y - - smtpd -o syslog_name=postfix/submission -o smtpd_tls_security_level=encrypt -o smtpd_tls_wrappermode=no -o smtpd_sasl_auth_enable=yes -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject -o smtpd_sasl_type=dovecot -o smtpd_sasl_path=private/auth - smtps inet n - y - - smtpd -o syslog_name=postfix/smtps -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject -o smtpd_sasl_type=dovecot -o smtpd_sasl_path=private/auth - smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 smtp_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 smtp_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 - [root@home home.wo-lar.com]# ss -lnpt | grep master LISTEN 0 100 0.0.0.0:25 0.0.0.0:* users:(("master",pid=6985,fd=16)) LISTEN 0 100 0.0.0.0:587 0.0.0.0:* users:(("master",pid=6985,fd=20)) LISTEN 0 100 0.0.0.0:465 0.0.0.0:* users:(("master",pid=6985,fd=23)) - LISTEN 0 100 0.0.0.0:993 0.0.0.0:* users:(("dovecot",pid=7000,fd=45)) LISTEN 0 100 0.0.0.0:995 0.0.0.0:* users:(("dovecot",pid=7000,fd=26)) LISTEN 0 100 0.0.0.0:110 0.0.0.0:* users:(("dovecot",pid=7000,fd=24)) LISTEN 0 100 0.0.0.0:143 0.0.0.0:* users:(("dovecot",pid=7000,fd=43)) LISTEN 0 100 [::]:993 [::]:* users:(("dovecot",pid=7000,fd=46)) LISTEN 0 100 [::]:995 [::]:* users:(("dovecot",pid=7000,fd=27)) LISTEN 0 100 [::]:110 [::]:* users:(("dovecot",pid=7000,fd=25)) LISTEN 0 100 [::]:143 [::]:* users:(("dovecot",pid=7000,fd=44)) Thanks for helping Wolfgang Rauchholz +34 627 994 977 https://www.linkedin.com/in/wolfgangrauchholz/