I have several Postfix servers with virtually identical configurations. That is, they have their own hostnames, IP addresses, etc. But the rest of main.cf and master.cf and various *_access, etc. files are the same.
I recently started having a problem with SSL_accept errors on just one of the machines. Several people report (including me) that from the same Thunderbird client, we can connect to all of the other servers and send a message. But when we try to connect and send to the one server, it fails. The Thunderbird client displays: "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) host.domain timed out. Try again. /var/log/mail.log shows: Mar 25 21:35:19 w1xsc-gw postfix/submission/smtpd[9565]: connect from client.domain.org[xx.xx.xx.xx] Mar 25 21:35:19 w1xsc-gw postfix/submission/smtpd[9565]: SSL_accept error from client.domain.org[xx.xx.xx.xx]: Connection reset by peer Mar 25 21:35:19 w1xsc-gw postfix/submission/smtpd[9565]: lost connection after STARTTLS from client.domain.org[xx.xx.xx.xx] Mar 25 21:35:19 w1xsc-gw postfix/submission/smtpd[9565]: disconnect from client.domain.org[xx.xx.xx.xx] ehlo=1 starttls=0/1 commands=1/2 I tried setting smtpd_tls_loglevel = 2, in case the extra information is helpful: Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: connect from client.domain.org[xx.xx.xx.xx] Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: setting up TLS connection from client.domain.org[xx.xx.xx.xx] Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: client.domain.org[xx.xx.xx.xx]: TLS cipher list "aNULL:-aNULL:HIGH:MEDIUM:+RC4:@STRENGTH" Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: SSL_accept:before/accept initialization Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: SSL_accept:error in SSLv2/v3 read client hello A Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: SSL_accept error from client.domain.org[xx.xx.xx.xx]: Connection reset by peer Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: lost connection after STARTTLS from client.domain.org[xx.xx.xx.xx] Mar 25 21:43:34 w1xsc-gw postfix/submission/smtpd[9906]: disconnect from client.domain.org[xx.xx.xx.xx] ehlo=1 starttls=0/1 commands=1/2 I re-verified that the configs between the different Postfix machines are the same (except for the obvious IP address, etc.) and they haven't changed. I also looked at previous posts about SSL_accept but they didn't seem to be the same situation. Any idea of what's wrong? Or how to find out what's wrong? Thanks, Michael postconf -nf: alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases append_at_myorigin = yes append_dot_mydomain = yes biff = no body_checks = pcre:${config_directory}/body_checks.pcre bounce_queue_lifetime = 12h bounce_template_file = ${config_directory}/bounce.cf broken_sasl_auth_clients = yes canonical_maps = pcre:${config_directory}/canonical.pcre compatibility_level = 2 content_filter = amavisfeed:[127.0.0.1]:10024 delay_warning_time = 2h fast_flush_domains = $relay_domains header_checks = pcre:${config_directory}/header_checks.pcre html_directory = /usr/share/doc/postfix/html inet_interfaces = $xsc_inet_interfaces mailbox_size_limit = 51200000 maximal_queue_lifetime = 12h message_size_limit = 10240000 milter_default_action = accept milter_protocol = 6 mime_header_checks = pcre:${config_directory}/mime_header_checks.pcre mua_client_connection_count_limit = 5 mua_client_connection_rate_limit = 10 mua_client_message_rate_limit = 10 mua_client_recipient_rate_limit = 50 mua_client_restrictions = check_sasl_access hash:${config_directory}/sasl_access permit_sasl_authenticated reject mua_discard_ehlo_keyword_address_maps = cidr:${config_directory}/ehlo_keyword.cidr mua_helo_restrictions = mua_recipient_limit = 25 mua_recipient_overshoot_limit = 25 mua_recipient_restrictions = reject_non_fqdn_recipient reject_unknown_recipient_domain check_sasl_access hash:${config_directory}/sasl_access check_recipient_access hash:${config_directory}/roleaccount_exceptions check_recipient_access pcre:${config_directory}/recipient_access.pcre check_recipient_access pcre:${config_directory}/relay_recipient_access.pcre check_recipient_access pcre:${config_directory}/virtual_recipient_access.pcre permit mua_relay_restrictions = permit_sasl_authenticated reject mua_sender_restrictions = $mua_tls_client_restrictions reject_non_fqdn_sender reject_sender_login_mismatch permit_sasl_authenticated reject_unknown_sender_domain reject_unlisted_sender permit mua_tls_client_restrictions = check_client_access cidr:${config_directory}/tls_clients.cidr mydestination = $xsc_mydestination mydomain = $xsc_mydomain myhostname = $xsc_myhostname mynetworks = $xsc_mynetworks myorigin = $xsc_myorigin non_smtpd_milters = inet:localhost:8891 postscreen_access_list = permit_mynetworks cidr:${config_directory}/postscreen_access.cidr postscreen_blacklist_action = drop postscreen_dnsbl_action = enforce postscreen_dnsbl_reply_map = pcre:${config_directory}/postscreen_dnsbl_reply_map.pcre postscreen_dnsbl_sites = zen.spamhaus.org*3 bl.spameatingmonkey.net*2 psbl.surriel.com*2 bl.spamcop.net hostkarma.junkemailfilter.com=127.0.0.2 dnsbl.sorbs.net bl.mailspike.net swl.spamhaus.org*-4 list.dnswl.org=127.0.[0..255].0*-1 list.dnswl.org=127.0.[0..255].1*-2 list.dnswl.org=127.0.[0..255].2*-3 list.dnswl.org=127.0.[0..255].3*-4 postscreen_dnsbl_threshold = 3 postscreen_dnsbl_ttl = 5m postscreen_greet_action = enforce proxy_interfaces = $xsc_proxy_interfaces readme_directory = /usr/share/doc/postfix recipient_delimiter = + relay_domains = $xsc_relay_domains relay_recipient_maps = pcre:${config_directory}/relay_recipients.pcre relay_restrictions = check_sender_access pcre:${config_directory}/relay_sender_access.pcre remote_header_rewrite_domain = invalid.domain smtp_host_lookup = native smtp_tls_loglevel = 1 smtp_tls_mandatory_protocols = !SSLv2, !SSLv3 smtp_tls_note_starttls_offer = yes smtp_tls_protocols = !SSLv2, !SSLv3 smtp_tls_security_level = may smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) smtpd_client_connection_count_limit = 10 smtpd_client_connection_rate_limit = 20 smtpd_client_message_rate_limit = 20 smtpd_client_recipient_rate_limit = 200 smtpd_client_restrictions = permit_mynetworks check_client_access pcre:${config_directory}/client_access.pcre reject_unknown_reverse_client_hostname check_client_access hash:${config_directory}/client_whitelist check_reverse_client_hostname_access pcre:${config_directory}/fqrdns.pcre reject_rbl_client zen.spamhaus.org reject_rhsbl_reverse_client dbl.spamhaus.org permit smtpd_data_restrictions = reject_unauth_pipelining reject_multi_recipient_bounce permit smtpd_delay_reject = yes smtpd_error_sleep_time = 2s smtpd_etrn_restrictions = permit_mynetworks permit_sasl_authenticated reject smtpd_hard_error_limit = 10 smtpd_helo_required = yes smtpd_helo_restrictions = permit_mynetworks reject_invalid_helo_hostname reject_non_fqdn_helo_hostname reject_rhsbl_helo dbl.spamhaus.org check_helo_access pcre:${config_directory}/helo_access.pcre permit smtpd_junk_command_limit = 2 smtpd_milters = inet:localhost:8891 smtpd_recipient_limit = 100 smtpd_recipient_overshoot_limit = 100 smtpd_recipient_restrictions = reject_non_fqdn_recipient reject_unknown_recipient_domain check_recipient_access hash:${config_directory}/roleaccount_exceptions check_recipient_access pcre:${config_directory}/recipient_access.pcre check_recipient_access pcre:${config_directory}/relay_recipient_access.pcre check_recipient_access pcre:${config_directory}/virtual_recipient_access.pcre permit smtpd_reject_footer = \c. Diagnostic info: time ($localtime), client ($client_address:$client_port), server ($server_name). smtpd_reject_unlisted_recipient = yes smtpd_relay_restrictions = permit_mynetworks reject_unauth_destination permit smtpd_restriction_classes = relay_restrictions virtual_quota_restrictions smtpd_sasl_auth_enable = no smtpd_sasl_path = private/dovecot-auth smtpd_sasl_security_options = noanonymous, noplaintext smtpd_sasl_type = dovecot smtpd_sender_login_maps = hash:${config_directory}/sasl_senders pcre:${config_directory}/sasl_senders_default.pcre smtpd_sender_restrictions = reject_non_fqdn_sender permit_mynetworks reject_unknown_sender_domain reject_unlisted_sender reject_rhsbl_sender dbl.spamhaus.org check_sender_access pcre:${config_directory}/sender_access.pcre check_sender_mx_access cidr:${config_directory}/sender_mx_access.cidr permit smtpd_soft_error_limit = 5 smtpd_tls_always_issue_session_ids = yes smtpd_tls_auth_only = no smtpd_tls_cert_file = $xsc_smtpd_tls_cert_file smtpd_tls_key_file = $xsc_smtpd_tls_key_file smtpd_tls_loglevel = 2 smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtpd_tls_protocols = !SSLv2, !SSLv3 smtpd_tls_security_level = may smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache transport_maps = hash:${config_directory}/transport unknown_address_reject_code = 550 unknown_client_reject_code = 550 unknown_hostname_reject_code = 550 unverified_recipient_reject_code = 550 unverified_sender_reject_code = 550 virtual_alias_maps = hash:${config_directory}/virtual_aliases virtual_mailbox_domains = $xsc_virtual_mailbox_domains virtual_mailbox_maps = hash:${config_directory}/virtual_mailboxes virtual_quota_restrictions = check_policy_service inet:[127.0.0.1]:12340 virtual_transport = lmtp:unix:private/dovecot-lmtp xsc_inet_interfaces = all xsc_mydestination = $xsc_myhostname localhost.$mydomain localhost.localdomain localhost