我最近在Linode上使用Postfix，Dovecot和MySQL设置了一个邮件服务器。我可以从邮件客户端（Outlook）发送和接收邮件，但是任何时候我尝试从我设计的wordpress网站与用户发送邮件都行不通。这是错误日志的输出：
Oct 27 18:36:52 hostname postfix/master[29738]: reload -- version 2.11.0, configuration /etc/postfix
Oct 27 18:37:00 hostname postfix/master[29738]: terminating on signal 15
Oct 27 18:37:00 hostname postfix/master[8304]: daemon started -- version 2.11.0, configuration /etc/postfix
Oct 27 18:37:12 hostname postfix/smtpd[8309]: warning: hostname mydomain.com does not resolve to address 2a01:7e00::f03c:91ff:fecf:e7a6
Oct 27 18:37:12 hostname postfix/smtpd[8309]: connect from unknown[2a01:7e00::f03c:91ff:fecf:e7a6]
Oct 27 18:37:12 hostname postfix/smtpd[8309]: lost connection after UNKNOWN from unknown[2a01:7e00::f03c:91ff:fecf:e7a6]
Oct 27 18:37:12 hostname postfix/smtpd[8309]: disconnect from unknown[2a01:7e00::f03c:91ff:fecf:e7a6]
我的main.cf文件已设置为：
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
smtpd_tls_cert_file=/etc/dovecot/dovecot.pem
smtpd_tls_key_file=/etc/dovecot/private/dovecot.pem
smtpd_use_tls=yes
smtpd_tls_auth_only = yes
smtp_tls_security_level = may
smtpd_tls_security_level = may
dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = hostname.mydomain.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = mydomain.com, hostname.mydomain.com, localhost.mydomain.com, localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
message_size_limit = 20480000
virtual_transport = lmtp:unix:private/dovecot-lmtp
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf, mysql:/etc/postfix/mysql-virtual-email2email.cf
Oct 28 11:34:22 hostname postfix/smtpd[14321]: warning: hostname mydomain.com does not resolve to address 139.162.209.129 Oct 28 11:34:22 hostname postfix/smtpd[14321]: connect from unknown[139.162.209.129] Oct 28 11:34:22 hostname postfix/smtpd[14321]: lost connection after UNKNOWN from unknown[139.162.209.129] Oct 28 11:34:22 hostname postfix/smtpd[14321]: disconnect from unknown[139.162.209.129]