我构建了一个基于 Web 的应用程序，但是当它尝试发送电子邮件时失败了。Postfix 在它的 mail.log 中记录以下内容：
postfix/smtpd[22261]: warning: hostname srv.eastinc.nl does not resolve to address 192.168.3.101
postfix/smtpd[22261]: connect from unknown[192.168.3.101]
postfix/smtpd[22261]: NOQUEUE: reject: RCPT from unknown[192.168.3.101]: 554 5.7.1 <someaddress@gmail.com>: Relay access denied; from=<Domain@eastinc.nl> to=<someaddress@gmail.com> proto=ESMTP helo=<domain.eastinc.nl>
postfix/smtpd[22261]: disconnect from unknown[192.168.3.101]
我很确定 srv.eastinc.nl 解析为 192.168.3.101，因为 nslookup 是这样说的。后缀配置：
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
config_directory = /etc/postfix
delay_warning_time = 2h
home_mailbox = Maildir/
inet_interfaces = all
mailbox_size_limit = 0
mydestination = eastinc.nl, mail.eastinc.nl, srv.eastinc.nl, localhost.eastinc.nl, localhost …