我正在经历设置邮件服务器的过程。我写过电子商务、OOP、JS 等，这是迄今为止我经历过的最困难和最全面的考验。
我已将 postfix 设置为通过 mysql 数据库使用虚拟域和用户。我知道这到目前为止是有效的，因为当我故意更改数据库的用户表中的电子邮件地址时，我收到了如下所示的第一条消息。一旦我更正它，我就会收到第二条消息。
为什么我会收到以下（突出显示的）行？：
-- with incorrect database entry --
Jul 4 18:24:38 mailer postfix/smtpd[5109]: connect from unknown[67.205.1.1]
Jul 4 18:24:38 mailer postfix/smtpd[5109]: NOQUEUE: reject: RCPT from unknown[67.205.1.1]: 550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in virtual mailbox table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<tothebatcave.com>
Jul 4 18:24:38 mailer postfix/smtpd[5109]: disconnect from unknown[67.205.1.1] ehlo=1 mail=1 rcpt=0/1 data=0/1 rset=1 quit=1 commands=4/6
-- with database entry changed back --
Jul 4 18:25:22 mailer postfix/smtpd[5109]: connect from unknown[67.205.1.1]
Jul 4 18:25:22 mailer postfix/smtpd[5109]: 593F517B342: client=unknown[67.205.1.1]
Jul 4 18:25:22 mailer postfix/cleanup[5116]: 593F517B342: message-id=<[email protected]>
Jul 4 18:25:22 mailer postfix/qmgr[5082]: 593F517B342: from=<[email protected]>, size=542, nrcpt=1 (queue active)
Jul 4 18:25:22 mailer postfix/smtpd[5109]: disconnect from unknown[67.205.1.1] ehlo=1 mail=1 rcpt=1 data=1 quit=1 commands=5
#### -- here is where dovecot seems to be missing something --
#### -- (either from the handoff, or configuration? I don't know..) --
Jul 4 18:25:22 mailer postfix/pipe[5117]: 593F517B342: to=<[email protected]>, relay=dovecot, delay=0.05, delays=0.01/0.01/0/0.03, dsn=5.1.1, status=bounced (user unknown)
Jul 4 18:25:22 mailer postfix/cleanup[5116]: 642E017B348: message-id=<[email protected]>
Jul 4 18:25:22 mailer postfix/bounce[5120]: 593F517B342: sender non-delivery notification: 642E017B348
Jul 4 18:25:22 mailer postfix/qmgr[5082]: 642E017B348: from=<>, size=2627, nrcpt=1 (queue active)
Jul 4 18:25:22 mailer postfix/qmgr[5082]: 593F517B342: removed
Jul 4 18:25:22 mailer postfix/smtp[5121]: 642E017B348: to=<[email protected]>, relay=tothebatcave.com[67.205.1.1]:25, delay=0.07, delays=0/0.01/0.05/0.01, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 73FF7A23F1)
Jul 4 18:25:22 mailer postfix/qmgr[5082]: 642E017B348: removed
为了简单起见，我附上了设置conf.d/10-mail.cf（很多帖子都很长）。如有需要，我会附上更多，谢谢！
mail_home = /var/mail/vhosts/%d/%n
# mail_location = mbox:~/mail:INBOX=/var/www/%d/mail/%u
mail_location = maildir:~