Gmail将Dovecot电子邮件标记为不安全

我以为我成功保护了我的Postfix / Dovecot电子邮件服务器。 我有一个来自LetsEncrypt的签名证书，对我的域名有效。

发送和接收工作正常，但由于Gmail开始标记不安全的电子邮件，所有从我的服务器发送的邮件都被标记为未encryption。

Gmail用户看到“此消息未encryption”，如下所示：

• 无法获得SASL auxprop / sasldb与Postfix / Ubuntu 12.04一起工作
• postmap：fatal：打开数据库/etc/postfix/sasl_passwd.db：权限被拒绝
• 为什么我的邮件被标记为垃圾邮件？
• 我需要build议：小型内存占用Linux邮件服务器与垃圾邮件过滤
• 推荐的方式来实现Postfix的“队列前”SpamAssassin过滤？

在Postfix的main.cf和其他设置中，我有：

 # SASL, for SMTP authentication smtpd_sasl_type = dovecot smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous smtpd_sasl_path = private/auth # TLS, for encryption smtpd_tls_security_level = may smtpd_tls_auth_only = no smtpd_tls_CAfile = /etc/letsencrypt/live/mydomain.com/chain.pem smtpd_tls_cert_file = /etc/letsencrypt/live/mydomain.com/fullchain.pem smtpd_tls_key_file = /etc/letsencrypt/live/mydomain.com/privkey.pem tls_random_source = dev:/dev/urandom smtpd_client_new_tls_session_rate_limit = 10 smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_tls_exclude_ciphers = EXP EDH-RSA-DES-CBC-SHA ADH-DES-CBC-SHA DES-CBC-SHA SEED-SHA smtpd_tls_dh512_param_file = ${config_directory}/certs/dh_512.pem smtpd_tls_dh1024_param_file = ${config_directory}/certs/dh_1024.pem disable_vrfy_command = yes smtpd_helo_required = yes smtpd_delay_reject = yes 

在Postfix的master.cf ，除了其他设置外，我还有：

 smtp inet n - - - - smtpd -o smtpd_enforce_tls=yes -o smtpd_use_tls=yes -o smtpd_tls_security_level=encrypt submission inet n - - - - smtpd -o syslog_name=postfix/submission -o smtpd_tls_security_level=encrypt -o smtpd_sasl_auth_enable=yes -o broken_sasl_auth_clients=yes 

在Dovecot的10-ssl.conf ，除了其他设置之外，我还有：

 ssl = required ssl_ca = </etc/letsencrypt/live/mydomain.com/chain.pem ssl_cert = </etc/letsencrypt/live/mydomain.com/fullchain.pem ssl_key = </etc/letsencrypt/live/mydomain.com/privkey.pem 

是否Gmail错误地标记LetsEncrypt证书，因为它不信任它们，或者我的电子邮件确实是未encryption发送的？

 smtp_tls_security_level = may smtpd_tls_security_level = may 

 smtp_tls_security_level = may 

 # Force TLS for outgoing server connection smtp_tls_policy_maps = hash:/etc/postfix/tls_policy smtp_tls_CApath = /etc/postfix/rootcas/ 

 #/C=US/O=Equifax/OU=Equifax Secure Certificate Authority gmail.com secure ciphers=high google.com secure ciphers=high googlemail.com secure ciphers=high 

 gmail.com encrypt ciphers=high google.com encrypt ciphers=high googlemail.com encrypt ciphers=high 

 postmap /etc/postfix/tls_policy 

  +----------+ +----------+ +------+ | | | | | User |<-->| | SMTP | | +------+ | Client- |Commands/Replies| Server- | +------+ | SMTP |<-------------->| SMTP | +------+ | File |<-->| | and Mail | |<-->| File | |System| | | | | |System| +------+ +----------+ +----------+ +------+ SMTP client SMTP server