我一直在尝试将 Postfix 配置为使用 SMTP 身份验证。当我在端口 587 上 telnet 时，我的身份验证似乎正确，但邮件未能到达其目的地，而是返回为 553 被 Spamhaus 拒绝，因为我的 IP 在 PBL 上。当我阅读有关 Spamhaus 的文档时，我被告知在 PBL 上并不是一个障碍，我只需要确保我正确地进行身份验证（https://www.spamhaus.org/faq/section/Spamhaus%20PBL#253）。
我进行了广泛的搜索，但没有找到确保从该服务器成功发送邮件的方法。
有人知道我在这里可能会错过什么吗？
这是我的 telnet 测试的结果：
ubuntu@dev-server:~$ telnet api.mijnvitalefuncties.com 587
Trying 192.168.0.11...
Connected to api.mijnvitalefuncties.com.
Escape character is '^]'.
220 dev-server ESMTP Postfix (Ubuntu)
ehlo api.mijnvitalefuncties.com
250-dev-server
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
AUTH LOGIN
334 VXNlcm5hbWU6
***
334 UGFzc3dvcmQ6
***
235 2.7.0 Authentication successful
MAIL FROM:<[email protected]>
250 2.1.0 Ok
RCPT TO:<[email protected]>
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
.
250 2.0.0 Ok: queued as B70A764235
quit
221 2.0.0 Bye
Connection closed by foreign host.
这是我收到的电子邮件，通知我邮件无法投递：
This is the mail system at host dev-server.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<[email protected]>: host cluster5.eu.messagelabs.com[193.109.255.99]
said: 553-mail rejected because your IP is in the PBL. See 553
http://www.spamhaus.org/pbl (in reply to RCPT TO command)
这是我尝试禁用端口 25 以强制邮件通过提交（端口 587）时遇到的错误。
Jan 27 11:53:26 dev-server postfix/qmgr[16821]: warning: connect to transport private/smtp: Connection refused
Jan 27 11:53:26 dev-server postfix/error[16841]: 5137E64232: to=<[email protected]>, relay=none, delay=19, delays=19/0/0/0.01, dsn=4.3.0, status=deferred (mail transport unavailable)