Dovecot 和 Postfix 都运行良好。尤其适用于 Win 8+ 和 Mac OS 10.10+ 以及 iOS 8+ 机器。
但尝试从 10.9 Mavericks Mac 进行连接时却出现了奇怪的情况......
这是我的 main.cf
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mydestination =
mailbox_size_limit = 5120000000000000
message_size_limit = 30720000
recipient_delimiter =
inet_interfaces = all
myorigin = example.ddns.net
inet_protocols = all
# specify SMTP relay host
relayhost = [myhost]:587
##### TLS parameters ######
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
###### SASL Auth ######
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions =
permit_sasl_authenticated,
permit_mynetworks,
check_relay_domains
###### Use Dovecot LMTP Service to deliver Mails to Dovecot ######
virtual_transport = lmtp:unix:private/dovecot-lmtp
##### Only allow mail transport if client is authenticated or in own network (PHP Scripts, ...) ######
#smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
###### MySQL Connection ######
virtual_alias_maps = mysql:/etc/postfix/virtual/mysql-aliases.cf
virtual_mailbox_maps = mysql:/etc/postfix/virtual/mysql-maps.cf
virtual_mailbox_domains = mysql:/etc/postfix/virtual/mysql-domains.cf
local_recipient_maps = $virtual_mailbox_maps
# enable SASL authentication
smtp_sasl_auth_enable = yes
# disallow methods that allow anonymous authentication.
smtp_sasl_security_options = noanonymous
# where to find sasl_passwd
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
日志中的消息指出：
Jun 16 11:36:43 example postfix/smtpd[8038]: SSL_accept error from unknown[xxx]: lost connection
Jun 16 11:36:43 example postfix/smtpd[8038]: lost connection after STARTTLS from unknown[xxx]
Jun 16 11:36:43 example postfix/smtpd[8038]: disconnect from unknown[xxx4]
Jun 16 11:36:47 example postfix/submission/smtpd[8022]: auto_clnt_close: disconnect private/tlsmgr stream
然而我尝试在 465 和 587 上使用 SSL 进行连接，以及在 25 上使用非 SSL 进行连接。运行最新软件版本的其他客户端运行正常。
答案1
感谢@ychaouche，我找到了解决方案。
客户端不接受证书。这意味着不允许 SSL 传输。重新启动客户端邮件应用程序并信任此不受信任的 openssl 证书后，一切都按预期运行！
谢谢！