Dear postfix users, I'm running Postfix version 2.11.6 on an OpenSUSE 42.1 box and all is running sweet & fine ;) Except a customer calls me that he can't receive emails from one of his partners.
After looking for the partner email I found those log entries: 2017-01-14T00:31:28.312121+01:00 cx20 postfix/smtpd[12579]: connect from mail.kommunalunternehmen.de[217.6.53.146] 2017-01-14T00:31:28.419190+01:00 cx20 postfix/smtpd[12579]: SSL_accept error from mail.kommunalunternehmen.de[217.6.53.146]: Connection reset by peer 2017-01-14T00:31:28.420304+01:00 cx20 postfix/smtpd[12579]: lost connection after STARTTLS from mail.kommunalunternehmen.de[217.6.53.146] 2017-01-14T00:31:28.420870+01:00 cx20 postfix/smtpd[12579]: disconnect from mail.kommunalunternehmen.de[217.6.53.146] and those log entries repeat and repeat. From what I can also see in the logs it seems to be an exchange mail server: 2017-01-13T14:17:55.649227+01:00 cx20 postfix/cleanup[3703]: 960DA1A198A: message-id=<96C90C91ED31E24D8985DCEF2658CA0923EFD130@ku-exchange-02.kommunalunternehmen.local> is this a buggy or wrong configured MTA which has problems with TLS on port 25? All other MTA's don't seem to have any problems with TLS / STARTTLS. What can I do to fix this problem? Let the other MTA know that they got an issue with their TLS setup? Thanks & greetings Becki Here's my postconf, using a valid certificate from letsencrypt linux:~ # postconf -n | grep tls smtp_enforce_tls = no smtp_tls_CAfile = smtp_tls_CApath = smtp_tls_cert_file = /fullchain.pem smtp_tls_key_file = /privkey.pem smtp_tls_loglevel = 0 smtp_tls_session_cache_database = smtp_use_tls = yes smtpd_tls_CAfile = smtpd_tls_CApath = smtpd_tls_ask_ccert = no smtpd_tls_cert_file = /fullchain.pem smtpd_tls_key_file = /privkey.pem smtpd_tls_loglevel = 0 smtpd_tls_received_header = no smtpd_use_tls = yes tls_random_source = dev:/dev/urandom and here's a snippet from my master.cf smtp inet n - n - - smtpd amavis unix - - n - 2 smtp -o smtp_data_done_timeout=1200 -o smtp_send_xforward_command=yes -o disable_dns_lookups=yes -o max_use=20 #smtp inet n - n - 1 postscreen #smtpd pass - - n - - smtpd #dnsblog unix - - n - 0 dnsblog #tlsproxy unix - - n - 0 tlsproxy submission inet n - n - - smtpd -o syslog_name=postfix/submission -o smtpd_tls_security_level=encrypt -o smtpd_sasl_auth_enable=yes # -o smtpd_reject_unlisted_recipient=no # -o smtpd_client_restrictions=$mua_client_restrictions # -o smtpd_helo_restrictions=$mua_helo_restrictions # -o smtpd_sender_restrictions=$mua_sender_restrictions # -o smtpd_recipient_restrictions= -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o milter_macro_daemon_name=ORIGINATING 465 inet n - n - - smtpd -o syslog_name=postfix/smtps -o smtpd_tls_wrappermode=yes # -o content_filter=smtp:[127.0.0.1]:10024 -o smtpd_sasl_auth_enable=yes # -o smtpd_reject_unlisted_recipient=no # -o smtpd_client_restrictions=$mua_client_restrictions # -o smtpd_helo_restrictions=$mua_helo_restrictions # -o smtpd_sender_restrictions=$mua_sender_restrictions # -o smtpd_recipient_restrictions= -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o milter_macro_daemon_name=ORIGINATING --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus